================================================================================

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


                                    FORM 8-K

                                 CURRENT REPORT

                PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES
                              EXCHANGE ACT OF 1934

                                  April 4, 2001
                                (Date of Report)

                                 March 31, 2001
                        (Date of earliest event reported)


                            -------------------------

                         Commission File Number 0-26816

                             IDX SYSTEMS CORPORATION
             (Exact name of registrant as specified in its charter)


        Vermont                                        03-0222230
(State or other jurisdiction of                     (I.R.S. Employer
 incorporation or organization)                    Identification No.)

                               1400 Shelburne Road
                           South Burlington, VT 05403
                    (Address of principal executive offices)

Registrant's telephone number, including area code: (802-862-1022)





================================================================================

                             Exhibit Index on Page 2


<PAGE>


ITEM 5.  OTHER EVENTS

         On March 31, 2001,  the Company and WebMD  Corporation  entered into
Addendum I to their Agreement dated as of June 6, 2000.


ITEM 7.  FINANCIAL STATEMENTS AND EXHIBITS

(c)      Exhibits.

<TABLE>
<CAPTION>

         EXHIBIT NO.               DESCRIPTION                            PAGE
         -----------               -----------                            ----
         <S>                       <C>                                    <C>

         99.1                      Addendum I to Agreement by and         4
                                   between IDX Systems Corporation and
                                   WebMD Corporation as of
                                   March 31, 2001



</TABLE>
































                                     Page 2
<PAGE>

                                   SIGNATURES

Pursuant  to the  requirements  of the  Securities  Exchange  Act of  1934,  the
registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned hereunto duly authorized.

                                 IDX SYSTEMS CORPORATION
                                 (Registrant)



Date:  April 4, 2001             By:  /S/ JOHN A. KANE
                                    ___________________________________________
                                    John A. Kane
                                    Vice President, Finance and Administration
                                    Chief Financial Officer, and Treasurer



































                                     Page 3


<PAGE>
                                                                    Exhibit 99.1

   Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

                             ADDENDUM I TO AGREEMENT
================================================================================
This  Addendum I ("Addendum  I") to the  Agreement by and between WebMD and IDX,
effective as of June 6, 2000 (the  "Agreement") is entered into by IDX and WebMD
as of March 31, 2001.  The Agreement  shall continue in full force and effect as
modified by this Addendum I, and in the event of any  inconsistency  or conflict
between the terms of the  Agreement  and this  Addendum I, this Addendum I shall
control  and  govern.  The  identities  of the  parties  named  above  and other
capitalized  terms used herein are defined in the glossary found in the Glossary
section of this Addendum I.

1.       SERVICES
--------------------------------------------------------------------------------
         1.1.   ELECTRONIC TRANSACTIONS.

Delete  Section 1.1 of the Agreement in its entirety and insert the following in
lieu thereof:

          Through its Transaction  Services  Division known as "TSD," WebMD or a
          WebMD Affiliate shall be a non-exclusive source of, and shall provide,
          Financial EDI  Transactions for IDX's Practice  Management  Systems as
          set forth in the  Agreement  as  modified  by Addendum I. IDX shall be
          entitled  to promote  and market  WebMD as a source of  Financial  EDI
          Transactions for IDX Practice Management  Systems,  and WebMD shall be
          entitled to promote and market the fact that IDX makes WebMD's gateway
          available as a source of Financial  EDI  Transactions,  in  accordance
          with this Agreement.  IDX has no obligation to require any customer to
          submit any Financial EDI Transaction to WebMD or to the IDX Gateway.

          So long as WebMD meets the Featuring Conditions:

          (a) During the Exclusive  Period,  IDX (i) shall direct  Participating
          Payer  Batch  Claim  Transactions  to WebMD for  transmission  to such
          payers,  but  only  if  and  to  the  extent  that  IDX  or any of its
          Affiliates  is entitled  to  aggregate  and direct  such  transactions
          through the IDX Gateway or such  transactions  are subject to being so
          aggregated  and  directed  by IDX or any of its  Affiliates,  and (ii)
          shall not  promote,  market,  or recommend  Participating  Payer Batch
          Claim Transactions other than those of WebMD.

          (b)  During the  Featuring  Period,  IDX shall  promote,  market,  and
          recommend  the use of those  Financial EDI  Transactions  that are for
          Participating  Payers,  not less  favorably  than  those of any  other
          source  of such  transactions.  The fact  that an  alternative  source
          (other than IDX or an Affiliate of IDX) of financial EDI  transactions
          for  Participating  Payers  that is made  available  by IDX during the
          Featuring  Period may be offered  on  pricing  or other  terms  (which
          pricing  or other  terms  represent  the  terms of the  source of such
          transactions  and not IDX or an  Affiliate  of IDX) that  differ  from
          those of WebMD shall not, in and of itself,  constitute more favorable
          promotion,   marketing,  or  recommendation  by  IDX.  Notwithstanding
          anything to the  contrary  herein,  to the extent  that  Participating
          Payer  Batch  Claim  Transactions  or  Participating  Payer  Real Time
          Transactions  are  delivered   through  the  IDX  Gateway  during  the
          Featuring  Period,  IDX shall  deliver to WebMD for  delivery  to such
          Participating  Payers not less than [**],  as the case may be, [**] to
          any [**] including,  without  limitation,  [**]. With respect to [**],
          however,  [**]to  terminate  the effect of the  preceding  sentence by
          giving  WebMD  [**]  month's  advance  written  notice  containing  an
          explanation of its reasons for doing so.

          1.2.    GENERAL INTEGRATION OF SERVICES.

Delete  Section  1.2 of  the  Agreement  in its  entirety  and  insert  the
following in lieu thereof:  IDX and WebMD shall do the following in  furtherance
of this Agreement:

          (a)  Through  TSD,   WebMD  shall  work  with  IDX  to  assist  it  in
          integrating, and IDX shall integrate,  Financial EDI Transactions into
          IDX Practice Management Systems, through the IDX Gateway or otherwise,
          in IDX's  discretion,  as a standard feature available to customers of
          IDX Practice  Management Systems.  Notwithstanding the foregoing,  IDX
          shall [**] as of the date of this  Addendum I, [**].

--------------------------------------------------------------------------------
                                  Page 1 of 16
<PAGE>
   Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

          If subsequent to the date hereof, [**] or otherwise, [**] that are
          [**] IDX shall [**].

          (b) Through  TSD,  WebMD shall  support  IDX's  marketing  efforts for
          Financial EDI Transactions for Participating Payers.

          (c) With  respect to  customers  of IDX  Practice  Management  Systems
          submitting  transactions  through  the IDX  Gateway,  IDX  shall  have
          responsibility  for the enrollment,  registration  and installation of
          new  customers of Financial  EDI  Transactions,  and TSD shall provide
          reasonable assistance at its own expense.

          (d) Through TSD,  WebMD shall provide  service levels at least as high
          as set forth on the  Financial  Transactions  Service  Level  Schedule
          attached hereto.

          (e) IDX shall  notify TSD in writing of any Payers that it wants WebMD
          to add as a  Participating  Payer,  and  WebMD  shall  use  reasonable
          efforts to  promptly  do so. If any such payer is not added  within 60
          days of notice from IDX, then IDX shall not be bound by the provisions
          set forth in  Subsection  1.1(a) and 1.1(b) of Addendum I with respect
          to such payer.

          1.3.    PHYSICIAN PORTAL SERVICES.

Delete Section 1.3 of the Agreement in its entirety.

          1.4.    OUTREACH SERVICES.

Delete Section 1.4 of the Agreement in its entirety.

          1.5.    RIGHTS NECESSARY TO CARRY OUT OBLIGATIONS.

(No change.)

          1.6.    BRANDING.

(No change.)

          1.7.    NON-EXCLUSIVITY.

From Section 1.7 of the Agreement, delete "Nothing contained in this Agreement,"
and insert,  "Except for Section 1.1(a) of this Addendum I, nothing contained in
the Agreement or this Addendum I," in lieu thereof.

          1.8.    NON-AGGREGATION OF FINANCIAL EDI TRANSACTIONS.

[**],  IDX shall [**] and IDX shall [**] pursuant to the terms  hereof,  [**] or
otherwise,  unless such [**]. In the event that [**] or any of [**] in violation
of the prior sentence, [**] and at any time, [**] this Agreement,  subsequent to
[**] for IDX [**].  The  foregoing  shall [**] to an IDX [**] IDX may [**] of an
IDX [**], including without [**], that also [**] [**] or from [**] as a business
[**]

2. PRICING AND PAYMENT
--------------------------------------------------------------------------------
          2.1.    PAYMENTS.

Delete Section 2.1 of the Agreement in its entirety and replace it with the
following:  "The parties shall pay to each other the fees and revenue shares set
out   in   the    Payment    Schedule    attached    to   this    Addendum    I.
--------------------------------------------------------------------------------
                                  Page 2 of 16

<PAGE>
  Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

          2.2.    PAYMENT TERMS.

Delete "At" in the first line of Section 2.2 and insert, "Unless provided to the
contrary in the Payment Schedule, at" in lieu thereof.

          2.3.    RECORDS.

(No change.)

          2.4.    AUDIT RIGHTS.

(No change.)

          2.5.    TAXES.

(No change.)

3.        MANAGEMENT
--------------------------------------------------------------------------------
          3.1.    EXECUTIVE SPONSORSHIP.

(No change.)

          3.2.    PERSONNEL RESOURCES.

(No change.)

          3.3.   RELATIONSHIP BETWEEN THE PARTIES.

(No change.)

4.        TERM AND TERMINATION
--------------------------------------------------------------------------------
          4.1.   INITIAL TERM.

(No change.)

          4.2.   RENEWAL TERMS.

(No change.)

          4.3.   EARLY TERMINATION.

Insert, at the end of subsection (f) of Section 4.3, "in which event IDX may
exercise such right to terminate after [**].

          4.4.   EFFECTIVE DATE OF TERMINATION.

Delete the second occurrence of "4.3(e)" in line 3 of Section 4.4 and insert
"4.3(f)" in lieu thereof.

          4.5.   EFFECT OF TERMINATION.

(No change.)

          4.6.   POST-TERMINATION SUPPORT.

Delete  "than"  after  "up  to" in  line 2 of  Section  4.6.  Delete  "companies
comparable  to IDX," in line 4 of Section  4.6 and insert "any vendor of systems
similar to Practice Management Systems" in lieu thereof.

          4.7.   TERMINATION OF CERTAIN OBLIGATIONS.

Delete the first sentence of Section 4.7(a) and replace with the following:

(a) IDX may terminate one or more of its  obligations  under Section  1.1(a) and
1.1(b) if: (i) [**] that are [**] are [**] as to [**], or (ii) within [**] after

--------------------------------------------------------------------------------
                                  Page 3 of 16

<PAGE>
   Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

[**] of [**]that are for [**] are [**] at [**], or (iii) within [**]that are for
[**] that are [**] as is set forth on the Financial  Transactions  Service Level
Schedule annexed hereto.

5.        INTELLECTUAL PROPERTY.
--------------------------------------------------------------------------------
          5.1.    INTELLECTUAL PROPERTY RETAINED.

(No change.)

          5.2.    INTERFACES.
(No change.)

          5.3.    TRADEMARKS.

In line 2 of Section 5.3, insert, "or as otherwise may be contemplated pursuant
to Sections 6.3 and 11.4 of the Agreement and Sections 1.1 and 1.2 of the
Addendum I," after "otherwise expressly provided in this Agreement."

          5.4.    JOINTLY DEVELOPED MATERIALS.

Delete "or" in line 2 of Section 5.4 and insert "of" in lieu thereof.

6.        CONFIDENTIALITY.
--------------------------------------------------------------------------------
          6.1.    CONFIDENTIALITY OBLIGATIONS.

In line 12 of Section 6.1, insert "not" between "shall" and "create." Delete "a"
after  "limit" in line 14 of the same  section.  Add the following to the end of
the Section: Under no circumstances shall any of IDX's Confidential  Information
be disclosed to any Affiliate of WebMD,  or any  operating  unit within WebMD or
under  WebMD's  Control,  that is in the  business  of  marketing  any  Practice
Management System.

          6.2.    CONFIDENTIALITY OF DATA.

Delete Section 6.2 in its entirety and replace it with the following:

Each party  acknowledges  that data it  transmits as part of the  Financial  EDI
Transactions may include  customers'  confidential  information and confidential
medical information relating to patients.  Accordingly, each party agrees to use
commercially   reasonable   and   legally   required   efforts  to  protect  the
confidentiality   of  such  information  and  prevent  the  disclosure  of  such
information  to third  parties,  except  as may be  necessary  to carry  out its
obligations under this Agreement. The parties acknowledge and agree that nothing
contained in this Agreement shall be construed as requiring either party to this
Agreement  to  disclose  data to any other  person or  entity  in  violation  of
applicable  law, and each party agrees not to disclose any data if not permitted
to do so by  applicable  law.  IDX agrees  that  WebMD and all other  persons or
entities  involved in the operation of the Financial EDI Transactions as WebMD's
agents, have the right,  subject to applicable laws and consent of third parties
supplying  data, to transmit,  monitor,  retrieve,  store and use data as may be
necessary to carry out its  obligations  to provide  Financial EDI  Transactions
pursuant to this  Agreement as modified by Addendum I and to  De-Identify  data.
Nothing  in this  Agreement  shall  prohibit  WebMD  from  using  or  disclosing
De-Identified Data unless prohibited by law.

[**] the use of [**] any person or entity [**],  then the  provisions of Section
1.1 and 1.2 shall [**] that such [**] to such [**] shall be [**]this Agreement.

--------------------------------------------------------------------------------
                                  Page 4 of 16

<PAGE>

          6.3.    AGREEMENT CONFIDENTIAL.

(No change.)

          6.4.    DISCLOSURE REQUIRED TO COURT OR GOVERNMENT.

(No change.)

          6.5.    NO REMOVAL OF PROPRIETARY LEGENDS.

(No change.)

7.        REPRESENTATIONS AND WARRANTIES.
--------------------------------------------------------------------------------
          7.1.    SERVICES.

(No change.)

          7.2.    NON-INFRINGEMENT.
(No change.)

          7.3.    SYSTEM ENVIRONMENTS.

(No change.)

          7.4.    COMPLIANCE WITH LAWS.

Delete Section 7.4 in its entirety and replace it with the following:

Each party  represents,  warrants and  covenants to the other that, at all times
during the term of this Agreement and  thereafter,  it shall be responsible  for
complying  with all laws that are directly  applicable to its operations and the
operations of its Affiliates involved in performing this Agreement, but makes no
representation  or warranty as to any other  person's  operations.  Each party's
warranty extends (without limitation) to (a) laws governing its use or operation
of the Financial  EDI  Transactions,  (b) laws  governing  the  gathering,  use,
transmission,  processing,  receipt, reporting,  disclosure,  privacy, security,
maintenance, and storage of data, such as HIPAA, (c) anti-kickback laws, and (d)
laws governing the submission of claims for reimbursement of medical services.

          7.5.    DATA.

Delete Section 7.5 in its entirety and replace with the following:

IDX represents and warrants to WebMD that IDX will use  commercially  reasonable
efforts  to obtain in its  contracts  with  physicians  all  rights,  authority,
consents or permissions  legally necessary for IDX and, at IDX's request,  WebMD
to submit,  view,  access,  disclose,  process,  retrieve,  and transmit data in
connection with the Financial EDI  Transactions.  IDX hereby appoints WebMD, and
WebMD  accepts  such  appointment,  as IDX's  limited  agent for the  purpose of
transmitting patient medical data to other payers, physicians, and other medical
service  providers using Financial EDI Transactions for such patient.  WebMD and
IDX each  represent  to the  other  that  they  have not  been  prohibited  from
participating  in any Federal of state program  applicable  to the  transactions
contemplated  hereunder  and if it shall  become  so  prohibited,  the other may
immediately  terminate this  Agreement.

WebMD and IDX shall enter into  mutually  acceptable  agreements  as may be
required by final regulations promulgated under the Health Insurance Portability
and Accountability Act of 1996.

          7.6.    DUE ORGANIZATIONS.

(No change.)

          7.7.    NO BANKRUPTCY.

(No change.)

          7.8.    DISCLAIMERS.

(No change.)
--------------------------------------------------------------------------------
                                  Page 5 of 16

<PAGE>
8.        LIMITATION ON REMEDIES.
--------------------------------------------------------------------------------
(No change.)

9.        DEFENSE AND INDEMNIFICATION.
--------------------------------------------------------------------------------
          9.1.    LIMITED COVENANT TO DEFEND.

Delete Section 9.1 in its entirety and insert the following in lieu thereof:

Each party (the "Defending  Party"), at its own expense and subject to the terms
and conditions of this Section 9.1, will defend claims brought against the other
party (the  "Invoking  Party") in the United States by third parties (other than
affiliates of the Invoking  Party) to the extent that (a) bodily injury,  death,
wrongful disclosure of patient or confidential information, or tangible property
damage  proximately  results  from the  Defending  Party's (i) breach of a duty,
representation,  warranty or  obligation  of this  Agreement,  or (ii)  tortious
negligence or misconduct,  (b) the claim, if true,  would constitute a breach by
the Defending Party of the representations,  warranties,  covenants set forth in
Section  7.2,  7.4, or (c) the claim,  if true,  arises  from a wrongful  act or
omission of WebMD as agent of IDX  pursuant  to Section  7.5 above.  The defense
shall only extend to those portions of the claim.

          9.2.    CONDITIONS FOR DEFENSE.

(No change.)

          9.3.    INJUNCTIONS OBTAINED BY THIRD PARTIES.

(No change.)

          9.4.    EXPENSES AND MONETARY AWARDS.

(No change.)

          9.5.    ADDITIONAL COUNSEL.

(No change.)

          9.6.    EXCEPTIONS TO DUTIES TO DEFEND AND INDEMNIFY.

(No change.)

10.       DISPUTE RESOLUTION.
--------------------------------------------------------------------------------
          10.1.    DISPUTE RESOLUTION.

(No change.)

          10.2.    EXCEPTIONS.

(No change.)

          10.3.    PROGRESSIVE DISPUTE NEGOTIATION PROCEDURES.

(No change.)

11.       MISCELLANEOUS.
--------------------------------------------------------------------------------
          11.1.    NO REIMBURSEMENT.

(No change.)

          11.2.    FORCE MAJEURE.

Add the following to the end of this Section:

--------------------------------------------------------------------------------
                                  Page 6 of 16

<PAGE>
Each party  acknowledges  that the  other's  ability to provide  data under this
Agreement may be delayed or prevented by third parties,  and neither party shall
be responsible for such delay.

          11.3.    ASSIGNMENT.

(No change.)

          11.4.    NO WAIVER.

(No change.)

          11.5.    GOVERNING LAW; JURISDICTION; VENUE.

(No change.)

          11.6.    HEADINGS.

(No change.)

          11.7.    SEVERABILITY.

 (No change.)

          11.8.    NO BIAS.

(No change.)

          11.9.   COSTS, ATTORNEYS' FEES, AND EXPERTS' FEES.

(No change.)

          11.10.  COUNTERPARTS.

(No change.)

          11.11.  NOTICES.

Delete the words "on the first page of this Agreement" and replace with "in the
definitions of 'IDX' and 'WebMD' respectively."

          11.12.  ADEQUACY OF CONSIDERATION.

(No change.)

          11.13.  INSURANCE.

(No change.)

          11.14.  PUBLICITY.

(No change.)

          11.15.  ENTIRE AGREEMENT.

Insert at the beginning of Section 11.15,  "This Addendum I shall have no effect
whatsoever on the agreement between WebMD and ChannelHealth."

          11.16.  NO THIRD PARTY BENEFICIARIES.

(No change.)

          11.17.  NON-HIRE.

(No change.)

          11.18.  STOCK OPTION AGREEMENT.
--------------------------------------------------------------------------------
                                  Page 7 of 16

<PAGE>
  Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

Delete Section 11.18 in its entirety.

          11.19.  PAYMENTS.

Insert the following additional section:

          11.19.  Payments.

          Not later than [**],  WebMD shall pay IDX the sum of $[**] in full and
          final  satisfaction  of all amounts due on account under the Agreement
          for the period from [**]. IDX shall pay WebMD the sum of $[**] in full
          and final  satisfaction  for all claims for amounts due on account for
          the period from [**].  For  charges  incurred  after such  dates,  the
          parties shall make payments according to the rates and schedule as set
          forth in the Agreement and as modified by Addendum I.

          11.20.  MUTUAL RELEASES.

Insert the following additional section:

          11.20 Mutual releases.

          (a) By IDX. IDX and its  Affiliates  hereby fully and forever  release
          WebMD, its Affiliates,  officers,  agents, directors and employees and
          officers, directors and employees of each Affiliate of WebMD, from all
          actions,  causes of action,  suits,  debts,  dues,  expenses,  sums of
          money, accounts, costs, reckonings,  interests,  deficiencies,  bonds,
          bills, specialties,  covenants,  commission contracts,  controversies,
          agreements,   promises,  variances,  trespasses,  damages,  judgments,
          executions,  claims,  and  demands  whatsoever  in law,  admiralty  or
          equity, against WebMD and its Affiliates ("IDX Claims"), which IDX and
          its  Affiliates  (or any of them) ever had, now have or hereafter can,
          shall or may have for, upon or by reason of any manner,  cause, thing,
          claim,  contention  or  allegation  whatsoever  that arose or occurred
          prior to the Effective Date of the addendum based upon, in whole or in
          part,  this  Agreement,  other than IDX Claims arising on or after the
          Effective  Date of Addendum I due to a breach by WebMD on or after the
          Effective Date of Addendum I.

          (b) By WebMD.  WebMD and its Affiliates  fully and forever release IDX
          and its  Affiliates,  officers,  agents,  directors  and employees and
          officers,  directors and  employees of each  Affiliate of IDX from all
          actions,  causes of action,  suits,  debts,  dues,  expenses,  sums of
          money, accounts, costs, reckonings,  interests,  deficiencies,  bonds,
          bills, specialties,  covenants,  commission contracts,  controversies,
          agreements,   promises,  variances,  trespasses,  damages,  judgments,
          executions,  claims,  and  demands  whatsoever  in law,  admiralty  or
          equity,  against IDX and its Affiliates ("WebMD Claims"),  which WebMD
          and its  Affiliates  (or any of them) ever had,  now have or hereafter
          can,  shall or may have for,  upon or by reason of any manner,  cause,
          thing,  claim,  contention  or  allegation  whatsoever  that  arose or
          occurred  prior to the  Effective  Date of Addendum I based  upon,  in
          whole or in part this Agreement, other than WebMD Claims arising on or
          after the  Effective  Date of  Addendum I due to a breach by IDX on or
          after the Effective Date of Addendum I.

12.       AMENDED AND RESTATED GLOSSARY
--------------------------------------------------------------------------------
Delete the  Glossary  set forth in Section  12 of the  Agreement  and insert the
following in lieu thereof.

         Amended and Restated Glossary

         "Affiliate"  has the meaning set forth in rule 12(b) of the  Securities
         Act of  1934.  For the  purposes  of  calculating  fees due to IDX from
         WebMD,  "Affiliates"  shall not  include  any  clearinghouse  or claims
         processing  service to which WebMD pays fees,  provided  WebMD does not
         Control,  is not  Controlled  by, or is not under common  Control with,
         such  clearinghouse  or claims  processing  service.  Affiliates of IDX
         shall not include Allscripts Healthcare Solutions,  Inc., Channelhealth
         Incorporated, or any entity Controlled by, Controlling, or under common
         Control with either of them.

          "Confidential Information" means (i) any data or information,  oral or
         written,  that relates to any party's business practices or activities;
         (ii) any information,  ideas, know-how, trade secrets,  specifications,
         designs,  plans,  flow-charts,   drawings,  research  and  development,
         processes,  procedures  and market  research;  (iii) any source code or
         executable code versions of software;  and (iv) any other  information,
         regardless  of  form,  for  which  a  party  would  have  a  reasonable
         expectation of  confidentiality.  Confidential  Information  shall also
         include the terms and conditions of this Agreement.
--------------------------------------------------------------------------------
                                  Page 8 of 16

<PAGE>
  Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.


          "Control,"  "Controlled  by,"  "Controlling"  and similar  terms shall
          mean, with respect to an Entity:

          (i) The  acquisition (other than from the Entity under  consideration)
          by any  person,  entity or  "group",  within  the  meaning  of Section
          13(d)(3)  or  14(d)(2)  of the  Securities  Exchange  Act of 1934 (the
          "Exchange Act"), of beneficial ownership,  (within the meaning of Rule
          13d-3  promulgated  under the Exchange  Act) of fifty percent (50%) or
          more of either  the then  outstanding  shares  of common  stock or the
          combined  voting  power  of  the  Entity's  then  outstanding   voting
          securities entitled to vote generally in the election of directors; or

          (ii)Approval  by the  stockholders  of the party of a  reorganization,
          merger, consolidation, in each case, with respect to which persons who
          were  the  stockholders  of  the  party   immediately  prior  to  such
          reorganization,   merger   or   consolidation   do  not,   immediately
          thereafter,  own more than fifty percent (50%) of the combined  voting
          power  entitled to vote  generally in the election of directors of the
          reorganized,  merged or consolidated  Entity's then outstanding voting
          securities,  or a liquidation  or  dissolution of the Entity or of the
          sale of all or substantially all of the assets of the Entity.

          "Current Volume" means the volume of  Participating  Payer Batch Claim
          Transactions  submitted  during  the  month  of  April  2001,  whether
          submitted  via the  IDX  Gateway  or  otherwise  from an IDX  Practice
          Management System, determined as set forth in Section 5 of the Payment
          Schedule attached to Addendum I.

          "De-Identified  Data"  means  data  from  which  information  has been
          removed as required by law (including without limitation HIPAA), or if
          no law is applicable,  removed according to a commercially  recognized
          standard,  so  that  what  remains  of  such  data  cannot  be used to
          personally or otherwise  identify the individual or entity that is the
          subject of such data (such as names, social security numbers, employer
          I.D. numbers, addresses, and other identifying data).

          "Effective  Date" means June 6, 2000 with respect to the Agreement and
          March 31, 2001 with respect to Addendum I.

          "Entity" means any legal or natural person and any Affiliate  thereof.

          "Exclusive  Period"  means the period from the date of this Addendum I
          until [**].

          "Featured" shall be a term that applies only with respect to Financial
          EDI Transactions that are for Participating Payers and shall mean with
          respect to promotion and  integration of WebMD's  related  transaction
          services,  the  obligations  of IDX to perform as set forth in Section
          1.1(b) of Addendum I.

          "Featuring Conditions" means Sections 4.7(a)(i),(ii), and (iii) of the
          Agreement as amended by Addendum I.

          "Featuring  Period"  means  the  period  from the date of  Addendum  I
          through [**].

          "Financial   EDI   Transactions"   means  the   following  of  WebMD's
          financial-related,  medical  electronic  transactions  accomplished by
          electronic  data  interchange  or the  Internet:  medical  claims  and
          encounters, UB-92 claims originating from providers but not hospitals,
          electronic  remittance  advice,  eligibility,  referrals,  and  claims
          status updates.

          "HIPAA" means the Health Insurance  Portability and Accountability Act
          of 1996, as amended.

          "IDX"  means IDX  Systems  Corporation,  a Vermont  corporation,  with
          principal offices at 40 IDX Drive, South Burlington, Vermont 05403.

          "IDX  Gateway"  means a system  provided  by IDX for  aggregating  and
          switching electronic data interchange transactions.

          "Intellectual Property" means patents, copyrights, trademarks, service
          marks,  trade names,  trade dress,  domain names, Web sites,  logos or
          other proprietary rights.

          "Interfaces" means data maps,  software,  protocols,  translations and
          other  functionality  that facilitate the organization and transfer of
          data.

          "Marks" means trademarks,  service marks,  trade names, logos and such
          other business identifiers.

          "Non-Participating  Payer" means any Payer that is not a Participating
          Payer.

          "Non-Participating  Payer Batch Claim  Transaction"  means  electronic
          batch claim  transactions  (excluding  UB-92 claims  originating  from
--------------------------------------------------------------------------------
                                  Page 9 of 16

<PAGE>
          hospitals  as  distinguished  from  providers)  originating  from  IDX
          Practice Management System and sent via the IDX Gatewayto WebMD or any
          Affiliates of WebMD for submission in batches and not in Real Time for
          processing by or for a Non-Participating Payer.

          "Non-Participating  Payer  Real  Time  Transaction"  means  electronic
          non-batch   (Real-Time)    eligibility   and   referrals   transaction
          originating from IDX Practice  Management  Systems and that is sent to
          WebMD or any Affiliate of WebMD via the IDX Gateway for  processing by
          or for a Non-Participating Payer.

          "Participating  Payer" means any Payer that pays any  consideration to
          WebMD for  transactions,  regardless of the method or form of payment.
          However,  for the purpose of calculating fees due to IDX from WebMD on
          Transactions with Participating  Payers, such term shall not include a
          clearinghouse  or claims  processing  service to which WebMD pays fees
          and which is not an Affiliate of WebMD.

          "Participating  Payer Batch Claim  Transaction" means electronic batch
          claim transactions  (excluding UB-92 claims originating from hospitals
          as  distinguished  from  providers)   originating  from  IDX  Practice
          Management  Systems and sent to WebMD or any  Affiliates  of WebMD for
          submission in batches and not in real time to Participating Payers for
          processing  by or for  such  Participating  Payers.  However,  for the
          purpose of calculating fees due to IDX from WebMD on Transactions with
          Participating  Payers,  "Participating  Payer Batch Claim Transaction"
          shall not include  transactions  submitted to WebMD by a clearinghouse
          or claims processing service to which WebMD pays fees and which is not
          an Affiliate of WebMD.

          "Participating Payer Real Time Transaction" means electronic non-batch
          (Real-Time) eligibility and referrals transaction originating from IDX
          Practice Management Systems and that is sent to WebMD or any Affiliate
          of WebMD for processing by or for a Participating Payer.  However, for
          the purpose of calculating  fees due to IDX from WebMD on Transactions
          with Participating Payers, "Participating Payer Real Time Transaction"
          shall not include  transactions  submitted to WebMD by a clearinghouse
          or claims processing service to which WebMD pays fees and which is not
          an Affiliate of WebMD.

          "Payer" means any entity,  such as an insurance company,  managed care
          organization,  fiscal intermediary,  fiscal carrier,  fiscal agent, or
          information  services,  that pays claims  resulting from EDI Financial
          Transactions.

          "Payment  Schedule"  means the new payment  schedule  attached to this
          Addendum I in lieu of the Payment Schedule attached to the Agreement.

          "Practice  Management  System"  shall  mean any  software  application
          expressly  designed  and/or marketed by IDX, or any of its Affiliates,
          to automate the business  processes  of physician  billing,  physician
          scheduling,  managed care contract  administration,  hospital clinical
          practice,    physician    clinical    practice,    hospital    patient
          administration,  or hospital billing,  including by way of example and
          not in  limitation,  as embodied in the  products  currently  marketed
          under the trademarks "GPMS" and "IDXtendR."

          "Real-Time" means not in a batch mode.

          "Term"  means  collectively  the Initial Term and each Renewal Term as
          defined in Sections 4.1 and 4.2 of the Agreement.

          "WebMD"  means WebMD  Corporation,  a Delaware  corporation  (formerly
          known as  Healtheon/WebMD  Corporation)  with principal offices at 669
          River   Drive,   Center  Two,   Elmwood   Park,   New  Jersey   07407.
--------------------------------------------------------------------------------
                                 Page 10 of 16


<PAGE>


        IN WITNESS  WHEREOF , the  parties  hereto have executed this Agreement.

IDX SYSTEMS CORPORATION



By: /S/ RICHARD E. TARRANT
    ------------------------------------------
         (authorized signature)



Name: Richard E. Tarrant
      ----------------------------------------
         (printed)


Title: C.E.O.
       ---------------------------------------


Date:  3/30/01
      ----------------------------------------




WebMD CORPORATION



By: /S/ MICHAEL B GLICK
    ------------------------------------------
         (authorized signature)



Name: Michael B. Glick
      ----------------------------------------
         (printed)


Title: Senior Vice President - Legal
       ---------------------------------------


Date:  3/30/01
      ----------------------------------------

--------------------------------------------------------------------------------
                                 Page 11 of 16

<PAGE>
  Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

                                PAYMENT SCHEDULE

1.   PARTICIPATING PAYER BATCH CLAIM TRANSACTION FEES.

(a)       PREFERRED RATE. For Participating  Payer Batch Claim  Transactions
          submitted  prior to [**],  [**],  the fees payable by WebMD to IDX for
          every such  claim  shall be [**] the fees  collected  by webmd and all
          Affiliates of WebMD from Participating  Payers for such claims or (ii)
          $[**]. This shall be referred to as the "Preferred Rate."

(b)       ORDINARY RATE.  From and after [**], the applicable  rate for fees
          payable by WebMD for  Participating  Payer  Batch  Claim  Transactions
          shall be calculated  pursuant to Table I below. This shall be referred
          to as the "Ordinary Rate."

(c)       ADJUSTMENT.  IDX's claims  volume for  Participating  Payer Batch
          Claim  Transactions shall be measured for the month of [**]. If during
          such month,  IDX's claims volume for such  transactions  shall be less
          than [**] times the Current Volume, then for the [**] period, the fees
          payable  to  IDX  by  WebMD  for  Participating   Payers  Batch  Claim
          Transactions  shall not be calculated at the Preferred Rate, but shall
          be calculated at the Ordinary Rate.  However,  the preceding  sentence
          shall not apply if the volume is greater than [**]transactions in such
          month. If for any month prior to [**], IDX's claim volume is such that
          it would  receive  greater fees at the Ordinary  Rate,  then that rate
          shall apply for such month.

(d)       CERTAIN MINIMUM RATE. Notwithstanding the foregoing, for any month
          from and after [**] during the term of the Agreement  that IDX's total
          monthly  volume of  Participating  Payer Batch Claim  Transactions  is
          equal to or exceeds [**] times the Current  Volume,  or in any case if
          such volume  exceeds  [**]  million  claims,  then the fees payable by
          WebMD for such transactions  during such month shall be the greater of
          (i) the Preferred Rate and (ii) the Ordinary Rate.

2.   OTHER PARTICIPATING PAYER TRANSACTIONS.

     Notwithstanding  anything to the contrary herein, WebMD shall not be liable
     to make any  payments  to IDX  pursuant  to this  Section 2 of the  Payment
     Schedule [**]submits [**].

(a)       ELIGIBILITY  AND REFERRAL  TRANSACTIONS.  For every  Participating
          Payer  Real  Time  Transaction,  WebMD  shall pay IDX [**] of the fees
          collected  by WebMD and all  Affiliates  of WebMD  from  Participating
          Payers for such transaction.

(b)       ELECTRONIC REMITTANCE TRANSACTIONS. In recognition of the evolving
          nature of  remittance  transactions,  the  parties  shall  attempt  to
          negotiate fees for remittances  involving  Participating Payers. There
          shall be no obligations  with respect to such  transactions  hereunder
          until and unless such fees are negotiated.

3.    NON-PARTICIPATING PAYER TRANSACTIONS FEES.

(a)       BATCH   CLAIMS   AND   REAL   TIME   TRANSACTIONS.   For   every
          Non-Participating Payer Batch Claim Transaction, and Non-Participating
          Payer Real Time  Transaction,  IDX shall pay WebMD the  greater of (x)
          [**] of fees collected by IDX [**] or (y) (i) $[**],  per  transaction
          in which the aggregate  amount of such  transactions  are less than or
          equal to [**]  million;  (ii)  $[**]  per  transaction  in  which  the
          aggregate  amount of such  transactions are less than or equal to [**]
          million;  or (iii)  $[**]  per  transaction  in any month in which the
          aggregate  amount of such  transactions are greater than [**] million.
          Notwithstanding the foregoing,  for all such transactions submitted by
          IDX  during  the  period  from the date of  Addendum  I through  [**],
          regardless  of the  volume of such  transactions,  IDX shall pay WebMD
          $[**] per transaction.

(b)       CERTAIN  ADJUSTMENTS.  The foregoing fee  arrangement set forth in
          Section  3(a)  of  this  Payment   Schedule  shall  apply  to  such  a
          transaction  when  [**],  but in such  event , IDX shall  [**] for all
          amounts  paid  [**],  up to the  amount  otherwise  payable  to  WebMD
          pursuant  to Section  3(a) of this  Payment  Schedule,  and any amount
          payable  in excess of such  amount  [**]  pursuant  to Table 1. To the
          extent that after the date hereof WebMD  obtains an  agreement  with a
          Non-commercial  Payer (defined  below) to submit claims to [**],  then
          for purposes of Section 3 of this Payment Schedule,  such fee shall be
          treated as set forth in the foregoing sentence. "Non-commercial Payer"
          means a Payer of claims under government  programs and Blue Cross/Blue
          Shield.
--------------------------------------------------------------------------------
                                 Page 12 of 16
<PAGE>
  Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.


(c)      ELECTRONIC  REMITTANCE  TRANSACTIONS.  In  recognition  of the evolving
         nature  of  remittance  transactions,  the  parties  shall  attempt  to
         negotiate  fees for  remittances  involving  Non-Participating  Payers.
         There  shall  be no  obligations  with  respect  to  such  transactions
         hereunder until and unless such fees are negotiated.

4.       PAYMENTS.

(a)      MONTHLY PAYMENTS. All payment shall be made monthly in arrears, except
         as provided below.

(b)      MONTHLY STATEMENTS.  Not later than the [**] day of each calendar month
         of the Term,  WebMD  shall  send to IDX and IDX  shall  send to WebMD a
         written  statement  of the actual  activity  and fees owed with respect
         thereto during the prior calendar month,  signed by an officer of WebMD
         or an officer of IDX, as the case may be, determined in accordance with
         the terms hereof together with the data and  assumptions,  if any, used
         to calculate the fees owed by WebMD to IDX or IDX to WebMD, as the case
         may be.

(c)      PAYMENTS. Not later than the [**] day of each calendar month commencing
         with the calendar  month of the Effective Date of Addendum I, WebMD pay
         all amounts due to IDX for the prior  calendar  month and IDX shall pay
         all amounts due to WebMD for the prior calendar month.

(d)      OBJECTION;  ESTIMATED  PAYMENTS.  If either party objects in writing to
         the  amounts  claimed  payable  as set  forth  in a  monthly  statement
         provided  by  the  other  party,  then  such  other  party  shall  make
         nevertheless  make an  estimated  payment not later than the end of the
         month in which the  objection is made,  which  estimated  payment shall
         include an amount on account  for  transactions  that shall be equal to
         the  average  daily  rate  for such  transactions  as  determined  with
         reference  to the  previous  Monthly  Statement,  times  the  number of
         business days during the month in dispute.

(e)      DISPUTE RESOLUTION.  The parties shall meet and confer to resolve any
         payment disputes within 30 days thereafter.  Any overpayment  shall be
         credited to the next month's payment.

5.       DETERMINATION OF CLAIMS ORIGINATING FROM AN IDX PRACTICE MANAGEMENT
         SYSTEM.

(a)      Within [**]days from the date hereof [**] with the following additional
         information: [**].  This list shall be Confidential Information.

(b)      In the Envoy  system the Tax ID number is used to create the  Submitter
         ID Number.  WebMD  shall  confirm  how the other  WebMD  clearinghouses
         assign Submitter IDs.

(c)      [**] an Envoy Submitter Number or other WebMD clearinghouse Submitter
         ID Number. WebMD shall cooperate with IDX [**] is in [**] in cases
         [**].

(d)      WebMD  shall  [**]  for  whom it can  identify  a  WebMD  clearinghouse
         Submitter  ID Number  except (a) for and only to the  extent  that [**]
         that is already  associated with a clearinghouse that is [**] through a
         Submitter  ID Number;  or (b) for and to the  extent  that [**] [**] is
         submitting  claims  through a different  vendor (such as POMIS  vendor,
         claims  aggregator;  repricer  or other  entity)  that is  receiving  a
         payment [**]. A Parent  Account Number shall be assigned [**] and shall
         be associated with each account [**].

(e)      Upon the request of IDX, WebMD shall provide IDX [**].

(f)      On a monthly  basis WebMD shall  provide a report to IDX (the  "Monthly
         Activity  Report") showing the claims activity for each submitter [**].
         The  payments  to IDX  from  WebMD  and  from  IDX to  WebMD  shall  be
         determined by this Monthly  Activity  Report.  IDX shall have [**] days
         from the  receipt of each  Monthly  Activity  Report to  challenge  the
         reported  activity for any  submitter on such report or the omission of
         any submitter from such report.

(g)      If  requested  by a party,  the parties  shall  repeat the process set
         forth herein to validate volumes from time to time.
--------------------------------------------------------------------------------
                                 Page 13 of 16

<PAGE>
   Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

                   Payment Schedule - Table 1 (Ordinary Rate)


                            TABLE 1 (ORDINARY RATE)

   WebMD shall pay IDX the portion of fees set forth in the column headed "%
   of Fees"*:

                PER CLAIM VOLUME REBATE                 % OF FEES

                  FROM           TO

                  [**]           [**]                   [**]%
                  [**]           [**]                   [**]%
                  [**]           [**]                   [**]%
                  [**]           [**]                   [**]%
                  [**]           [**]                   [**]%

* Fees do not include fees generated with the intervention of another (non-
WebMD Affiliate) clearinghouse or claims processing services to which WebMD
pays fees.








--------------------------------------------------------------------------------
                                 Page 14 of 16

<PAGE>
   Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

                  FINANCIAL TRANSACTIONS SERVICE LEVEL SCHEDULE

This Schedule  describes the minimum service levels necessary for support of EDI
Financial  Transactions  by WebMD (TSD).

ISSUE TYPES
--------------------------------------------------------------------------------
Each issue reported to the WebMD Support Team is subject to the following
turn-around  times stated below. WebMD must meet these turn-around times in
[**]% of all cases.


                TYPE OF ISSUE           TURN-AROUND TIME
                -------------           -----------------

                Question                [**] business days

                Problem                 [**] business days1

                Critical                [**] business day average

                Request                 Evaluated on a case-by-case basis


QUESTION
         A QUESTION is any inquiry  about the basic  functioning  of the service
         that is not answered or documented in a manual.

PROBLEM
         A PROBLEM  is any  situation  within  the  control  of WebMD  where the
         service  is not in  accordance  with  WebMD's  documentation  and whose
         solution  may require data  modification  or software  modification  by
         WebMD.   Problems  include  enrollment  issues,   report  availability,
         inappropriate claim rejections, any payer-specific problem, etc.

CRITICAL
         These are  certain  issues  within  the  control  of WebMD  that  WebMD
         considers  critical  and  gives  immediate  attention  to as  they  are
         reported.  CRITICAL issues are "business stoppers" for the customer and
         are the cases that IDX  considers  a priority  for  eCommerce  Support.
         Critical issues include those that would disable all IDX customers from
         submitting claims to WebMD or WebMD is unable to submit all claim files
         of IDX  customers  to all  payers.


----------------------------
1 Where a problem can only reasonably be addressed through software
modification, that will be communicated within[**] days, and the problem
will be fixed in the next scheduled release or modification.

--------------------------------------------------------------------------------
                                 Page 15 of 16
<PAGE>

REQUEST
         A REQUEST is a need for  additional service/setup  that is part of the
         standard  implementation and support cycle.  An  example  would be
         adding  new  providers  or groups in the enrollment process.










--------------------------------------------------------------------------------
                                 Page 16 of 16
[{"type": "8-K", "sequence": "1", "filename": "idx8k44.txt", "secsgml_size_bytes": 52515}]
{"company-data": {"conformed-name": "IDX SYSTEMS CORP", "cik": "0001001185", "assigned-sic": "7373", "irs-number": "030222230", "state-of-incorporation": "VT", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "000-26816", "film-number": "1595300"}, "business-address": {"street1": "1400 SHELBURNE RD", "street2": "PO BOX 1070", "city": "SOUTH BURLINGTON", "state": "VT", "zip": "05403", "phone": "8028621022"}, "mail-address": {"street1": "1400 SHELBURNE RD", "street2": "PO BOX 1070", "city": "SOUTH BURLINGTON", "state": "VT", "zip": "05403"}}
================================================================================

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM 8-K

                                 CURRENT REPORT

                PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES
                              EXCHANGE ACT OF 1934

                                  April 4, 2001
                                (Date of Report)

                                 March 31, 2001
                        (Date of earliest event reported)

                            -------------------------

                         Commission File Number 0-26816

                             IDX SYSTEMS CORPORATION
             (Exact name of registrant as specified in its charter)

        Vermont                                        03-0222230
(State or other jurisdiction of                     (I.R.S. Employer
 incorporation or organization)                    Identification No.)

                               1400 Shelburne Road
                           South Burlington, VT 05403
                    (Address of principal executive offices)

Registrant's telephone number, including area code: (802-862-1022)

================================================================================

                             Exhibit Index on Page 2
ITEM 5.  OTHER EVENTS

         On March 31, 2001,  the Company and WebMD  Corporation  entered into
Addendum I to their Agreement dated as of June 6, 2000.

ITEM 7.  FINANCIAL STATEMENTS AND EXHIBITS

(c)      Exhibits.
EXHIBIT NO.               DESCRIPTION                            PAGE
         -----------               -----------                            ----
99.1                      Addendum I to Agreement by and         4
                                   between IDX Systems Corporation and
                                   WebMD Corporation as of
                                   March 31, 2001
Page 2
SIGNATURES

Pursuant  to the  requirements  of the  Securities  Exchange  Act of  1934,  the
registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned hereunto duly authorized.

                                 IDX SYSTEMS CORPORATION
                                 (Registrant)

Date:  April 4, 2001             By:  /S/ JOHN A. KANE
                                    ___________________________________________
                                    John A. Kane
                                    Vice President, Finance and Administration
                                    Chief Financial Officer, and Treasurer

                                     Page 3
Exhibit 99.1

   Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

                             ADDENDUM I TO AGREEMENT
================================================================================
This  Addendum I ("Addendum  I") to the  Agreement by and between WebMD and IDX,
effective as of June 6, 2000 (the  "Agreement") is entered into by IDX and WebMD
as of March 31, 2001.  The Agreement  shall continue in full force and effect as
modified by this Addendum I, and in the event of any  inconsistency  or conflict
between the terms of the  Agreement  and this  Addendum I, this Addendum I shall
control  and  govern.  The  identities  of the  parties  named  above  and other
capitalized  terms used herein are defined in the glossary found in the Glossary
section of this Addendum I.

1.       SERVICES
--------------------------------------------------------------------------------
         1.1.   ELECTRONIC TRANSACTIONS.

Delete  Section 1.1 of the Agreement in its entirety and insert the following in
lieu thereof:

          Through its Transaction  Services  Division known as "TSD," WebMD or a
          WebMD Affiliate shall be a non-exclusive source of, and shall provide,
          Financial EDI  Transactions for IDX's Practice  Management  Systems as
          set forth in the  Agreement  as  modified  by Addendum I. IDX shall be
          entitled  to promote  and market  WebMD as a source of  Financial  EDI
          Transactions for IDX Practice Management  Systems,  and WebMD shall be
          entitled to promote and market the fact that IDX makes WebMD's gateway
          available as a source of Financial  EDI  Transactions,  in  accordance
          with this Agreement.  IDX has no obligation to require any customer to
          submit any Financial EDI Transaction to WebMD or to the IDX Gateway.

          So long as WebMD meets the Featuring Conditions:

          (a) During the Exclusive  Period,  IDX (i) shall direct  Participating
          Payer  Batch  Claim  Transactions  to WebMD for  transmission  to such
          payers,  but  only  if  and  to  the  extent  that  IDX  or any of its
          Affiliates  is entitled  to  aggregate  and direct  such  transactions
          through the IDX Gateway or such  transactions  are subject to being so
          aggregated  and  directed  by IDX or any of its  Affiliates,  and (ii)
          shall not  promote,  market,  or recommend  Participating  Payer Batch
          Claim Transactions other than those of WebMD.

          (b)  During the  Featuring  Period,  IDX shall  promote,  market,  and
          recommend  the use of those  Financial EDI  Transactions  that are for
          Participating  Payers,  not less  favorably  than  those of any  other
          source  of such  transactions.  The fact  that an  alternative  source
          (other than IDX or an Affiliate of IDX) of financial EDI  transactions
          for  Participating  Payers  that is made  available  by IDX during the
          Featuring  Period may be offered  on  pricing  or other  terms  (which
          pricing  or other  terms  represent  the  terms of the  source of such
          transactions  and not IDX or an  Affiliate  of IDX) that  differ  from
          those of WebMD shall not, in and of itself,  constitute more favorable
          promotion,   marketing,  or  recommendation  by  IDX.  Notwithstanding
          anything to the  contrary  herein,  to the extent  that  Participating
          Payer  Batch  Claim  Transactions  or  Participating  Payer  Real Time
          Transactions  are  delivered   through  the  IDX  Gateway  during  the
          Featuring  Period,  IDX shall  deliver to WebMD for  delivery  to such
          Participating  Payers not less than [**],  as the case may be, [**] to
          any [**] including,  without  limitation,  [**]. With respect to [**],
          however,  [**]to  terminate  the effect of the  preceding  sentence by
          giving  WebMD  [**]  month's  advance  written  notice  containing  an
          explanation of its reasons for doing so.

          1.2.    GENERAL INTEGRATION OF SERVICES.

Delete  Section  1.2 of  the  Agreement  in its  entirety  and  insert  the
following in lieu thereof:  IDX and WebMD shall do the following in  furtherance
of this Agreement:

          (a)  Through  TSD,   WebMD  shall  work  with  IDX  to  assist  it  in
          integrating, and IDX shall integrate,  Financial EDI Transactions into
          IDX Practice Management Systems, through the IDX Gateway or otherwise,
          in IDX's  discretion,  as a standard feature available to customers of
          IDX Practice  Management Systems.  Notwithstanding the foregoing,  IDX
          shall [**] as of the date of this  Addendum I, [**].

--------------------------------------------------------------------------------
                                  Page 1 of 16
Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

          If subsequent to the date hereof, [**] or otherwise, [**] that are
          [**] IDX shall [**].

          (b) Through  TSD,  WebMD shall  support  IDX's  marketing  efforts for
          Financial EDI Transactions for Participating Payers.

          (c) With  respect to  customers  of IDX  Practice  Management  Systems
          submitting  transactions  through  the IDX  Gateway,  IDX  shall  have
          responsibility  for the enrollment,  registration  and installation of
          new  customers of Financial  EDI  Transactions,  and TSD shall provide
          reasonable assistance at its own expense.

          (d) Through TSD,  WebMD shall provide  service levels at least as high
          as set forth on the  Financial  Transactions  Service  Level  Schedule
          attached hereto.

          (e) IDX shall  notify TSD in writing of any Payers that it wants WebMD
          to add as a  Participating  Payer,  and  WebMD  shall  use  reasonable
          efforts to  promptly  do so. If any such payer is not added  within 60
          days of notice from IDX, then IDX shall not be bound by the provisions
          set forth in  Subsection  1.1(a) and 1.1(b) of Addendum I with respect
          to such payer.

          1.3.    PHYSICIAN PORTAL SERVICES.

Delete Section 1.3 of the Agreement in its entirety.

          1.4.    OUTREACH SERVICES.

Delete Section 1.4 of the Agreement in its entirety.

          1.5.    RIGHTS NECESSARY TO CARRY OUT OBLIGATIONS.

(No change.)

          1.6.    BRANDING.

(No change.)

          1.7.    NON-EXCLUSIVITY.

From Section 1.7 of the Agreement, delete "Nothing contained in this Agreement,"
and insert,  "Except for Section 1.1(a) of this Addendum I, nothing contained in
the Agreement or this Addendum I," in lieu thereof.

          1.8.    NON-AGGREGATION OF FINANCIAL EDI TRANSACTIONS.

[**],  IDX shall [**] and IDX shall [**] pursuant to the terms  hereof,  [**] or
otherwise,  unless such [**]. In the event that [**] or any of [**] in violation
of the prior sentence, [**] and at any time, [**] this Agreement,  subsequent to
[**] for IDX [**].  The  foregoing  shall [**] to an IDX [**] IDX may [**] of an
IDX [**], including without [**], that also [**] [**] or from [**] as a business
[**]

2. PRICING AND PAYMENT
--------------------------------------------------------------------------------
          2.1.    PAYMENTS.

Delete Section 2.1 of the Agreement in its entirety and replace it with the
following:  "The parties shall pay to each other the fees and revenue shares set
out   in   the    Payment    Schedule    attached    to   this    Addendum    I.
--------------------------------------------------------------------------------
                                  Page 2 of 16
Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

          2.2.    PAYMENT TERMS.

Delete "At" in the first line of Section 2.2 and insert, "Unless provided to the
contrary in the Payment Schedule, at" in lieu thereof.

          2.3.    RECORDS.

(No change.)

          2.4.    AUDIT RIGHTS.

(No change.)

          2.5.    TAXES.

(No change.)

3.        MANAGEMENT
--------------------------------------------------------------------------------
          3.1.    EXECUTIVE SPONSORSHIP.

(No change.)

          3.2.    PERSONNEL RESOURCES.

(No change.)

          3.3.   RELATIONSHIP BETWEEN THE PARTIES.

(No change.)

4.        TERM AND TERMINATION
--------------------------------------------------------------------------------
          4.1.   INITIAL TERM.

(No change.)

          4.2.   RENEWAL TERMS.

(No change.)

          4.3.   EARLY TERMINATION.

Insert, at the end of subsection (f) of Section 4.3, "in which event IDX may
exercise such right to terminate after [**].

          4.4.   EFFECTIVE DATE OF TERMINATION.

Delete the second occurrence of "4.3(e)" in line 3 of Section 4.4 and insert
"4.3(f)" in lieu thereof.

          4.5.   EFFECT OF TERMINATION.

(No change.)

          4.6.   POST-TERMINATION SUPPORT.

Delete  "than"  after  "up  to" in  line 2 of  Section  4.6.  Delete  "companies
comparable  to IDX," in line 4 of Section  4.6 and insert "any vendor of systems
similar to Practice Management Systems" in lieu thereof.

          4.7.   TERMINATION OF CERTAIN OBLIGATIONS.

Delete the first sentence of Section 4.7(a) and replace with the following:

(a) IDX may terminate one or more of its  obligations  under Section  1.1(a) and
1.1(b) if: (i) [**] that are [**] are [**] as to [**], or (ii) within [**] after

--------------------------------------------------------------------------------
                                  Page 3 of 16
Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

[**] of [**]that are for [**] are [**] at [**], or (iii) within [**]that are for
[**] that are [**] as is set forth on the Financial  Transactions  Service Level
Schedule annexed hereto.

5.        INTELLECTUAL PROPERTY.
--------------------------------------------------------------------------------
          5.1.    INTELLECTUAL PROPERTY RETAINED.

(No change.)

          5.2.    INTERFACES.
(No change.)

          5.3.    TRADEMARKS.

In line 2 of Section 5.3, insert, "or as otherwise may be contemplated pursuant
to Sections 6.3 and 11.4 of the Agreement and Sections 1.1 and 1.2 of the
Addendum I," after "otherwise expressly provided in this Agreement."

          5.4.    JOINTLY DEVELOPED MATERIALS.

Delete "or" in line 2 of Section 5.4 and insert "of" in lieu thereof.

6.        CONFIDENTIALITY.
--------------------------------------------------------------------------------
          6.1.    CONFIDENTIALITY OBLIGATIONS.

In line 12 of Section 6.1, insert "not" between "shall" and "create." Delete "a"
after  "limit" in line 14 of the same  section.  Add the following to the end of
the Section: Under no circumstances shall any of IDX's Confidential  Information
be disclosed to any Affiliate of WebMD,  or any  operating  unit within WebMD or
under  WebMD's  Control,  that is in the  business  of  marketing  any  Practice
Management System.

          6.2.    CONFIDENTIALITY OF DATA.

Delete Section 6.2 in its entirety and replace it with the following:

Each party  acknowledges  that data it  transmits as part of the  Financial  EDI
Transactions may include  customers'  confidential  information and confidential
medical information relating to patients.  Accordingly, each party agrees to use
commercially   reasonable   and   legally   required   efforts  to  protect  the
confidentiality   of  such  information  and  prevent  the  disclosure  of  such
information  to third  parties,  except  as may be  necessary  to carry  out its
obligations under this Agreement. The parties acknowledge and agree that nothing
contained in this Agreement shall be construed as requiring either party to this
Agreement  to  disclose  data to any other  person or  entity  in  violation  of
applicable  law, and each party agrees not to disclose any data if not permitted
to do so by  applicable  law.  IDX agrees  that  WebMD and all other  persons or
entities  involved in the operation of the Financial EDI Transactions as WebMD's
agents, have the right,  subject to applicable laws and consent of third parties
supplying  data, to transmit,  monitor,  retrieve,  store and use data as may be
necessary to carry out its  obligations  to provide  Financial EDI  Transactions
pursuant to this  Agreement as modified by Addendum I and to  De-Identify  data.
Nothing  in this  Agreement  shall  prohibit  WebMD  from  using  or  disclosing
De-Identified Data unless prohibited by law.

[**] the use of [**] any person or entity [**],  then the  provisions of Section
1.1 and 1.2 shall [**] that such [**] to such [**] shall be [**]this Agreement.

--------------------------------------------------------------------------------
                                  Page 4 of 16
6.3.    AGREEMENT CONFIDENTIAL.

(No change.)

          6.4.    DISCLOSURE REQUIRED TO COURT OR GOVERNMENT.

(No change.)

          6.5.    NO REMOVAL OF PROPRIETARY LEGENDS.

(No change.)

7.        REPRESENTATIONS AND WARRANTIES.
--------------------------------------------------------------------------------
          7.1.    SERVICES.

(No change.)

          7.2.    NON-INFRINGEMENT.
(No change.)

          7.3.    SYSTEM ENVIRONMENTS.

(No change.)

          7.4.    COMPLIANCE WITH LAWS.

Delete Section 7.4 in its entirety and replace it with the following:

Each party  represents,  warrants and  covenants to the other that, at all times
during the term of this Agreement and  thereafter,  it shall be responsible  for
complying  with all laws that are directly  applicable to its operations and the
operations of its Affiliates involved in performing this Agreement, but makes no
representation  or warranty as to any other  person's  operations.  Each party's
warranty extends (without limitation) to (a) laws governing its use or operation
of the Financial  EDI  Transactions,  (b) laws  governing  the  gathering,  use,
transmission,  processing,  receipt, reporting,  disclosure,  privacy, security,
maintenance, and storage of data, such as HIPAA, (c) anti-kickback laws, and (d)
laws governing the submission of claims for reimbursement of medical services.

          7.5.    DATA.

Delete Section 7.5 in its entirety and replace with the following:

IDX represents and warrants to WebMD that IDX will use  commercially  reasonable
efforts  to obtain in its  contracts  with  physicians  all  rights,  authority,
consents or permissions  legally necessary for IDX and, at IDX's request,  WebMD
to submit,  view,  access,  disclose,  process,  retrieve,  and transmit data in
connection with the Financial EDI  Transactions.  IDX hereby appoints WebMD, and
WebMD  accepts  such  appointment,  as IDX's  limited  agent for the  purpose of
transmitting patient medical data to other payers, physicians, and other medical
service  providers using Financial EDI Transactions for such patient.  WebMD and
IDX each  represent  to the  other  that  they  have not  been  prohibited  from
participating  in any Federal of state program  applicable  to the  transactions
contemplated  hereunder  and if it shall  become  so  prohibited,  the other may
immediately  terminate this  Agreement.

WebMD and IDX shall enter into  mutually  acceptable  agreements  as may be
required by final regulations promulgated under the Health Insurance Portability
and Accountability Act of 1996.

          7.6.    DUE ORGANIZATIONS.

(No change.)

          7.7.    NO BANKRUPTCY.

(No change.)

          7.8.    DISCLAIMERS.

(No change.)
--------------------------------------------------------------------------------
                                  Page 5 of 16
8.        LIMITATION ON REMEDIES.
--------------------------------------------------------------------------------
(No change.)

9.        DEFENSE AND INDEMNIFICATION.
--------------------------------------------------------------------------------
          9.1.    LIMITED COVENANT TO DEFEND.

Delete Section 9.1 in its entirety and insert the following in lieu thereof:

Each party (the "Defending  Party"), at its own expense and subject to the terms
and conditions of this Section 9.1, will defend claims brought against the other
party (the  "Invoking  Party") in the United States by third parties (other than
affiliates of the Invoking  Party) to the extent that (a) bodily injury,  death,
wrongful disclosure of patient or confidential information, or tangible property
damage  proximately  results  from the  Defending  Party's (i) breach of a duty,
representation,  warranty or  obligation  of this  Agreement,  or (ii)  tortious
negligence or misconduct,  (b) the claim, if true,  would constitute a breach by
the Defending Party of the representations,  warranties,  covenants set forth in
Section  7.2,  7.4, or (c) the claim,  if true,  arises  from a wrongful  act or
omission of WebMD as agent of IDX  pursuant  to Section  7.5 above.  The defense
shall only extend to those portions of the claim.

          9.2.    CONDITIONS FOR DEFENSE.

(No change.)

          9.3.    INJUNCTIONS OBTAINED BY THIRD PARTIES.

(No change.)

          9.4.    EXPENSES AND MONETARY AWARDS.

(No change.)

          9.5.    ADDITIONAL COUNSEL.

(No change.)

          9.6.    EXCEPTIONS TO DUTIES TO DEFEND AND INDEMNIFY.

(No change.)

10.       DISPUTE RESOLUTION.
--------------------------------------------------------------------------------
          10.1.    DISPUTE RESOLUTION.

(No change.)

          10.2.    EXCEPTIONS.

(No change.)

          10.3.    PROGRESSIVE DISPUTE NEGOTIATION PROCEDURES.

(No change.)

11.       MISCELLANEOUS.
--------------------------------------------------------------------------------
          11.1.    NO REIMBURSEMENT.

(No change.)

          11.2.    FORCE MAJEURE.

Add the following to the end of this Section:

--------------------------------------------------------------------------------
                                  Page 6 of 16
Each party  acknowledges  that the  other's  ability to provide  data under this
Agreement may be delayed or prevented by third parties,  and neither party shall
be responsible for such delay.

          11.3.    ASSIGNMENT.

(No change.)

          11.4.    NO WAIVER.

(No change.)

          11.5.    GOVERNING LAW; JURISDICTION; VENUE.

(No change.)

          11.6.    HEADINGS.

(No change.)

          11.7.    SEVERABILITY.

 (No change.)

          11.8.    NO BIAS.

(No change.)

          11.9.   COSTS, ATTORNEYS' FEES, AND EXPERTS' FEES.

(No change.)

          11.10.  COUNTERPARTS.

(No change.)

          11.11.  NOTICES.

Delete the words "on the first page of this Agreement" and replace with "in the
definitions of 'IDX' and 'WebMD' respectively."

          11.12.  ADEQUACY OF CONSIDERATION.

(No change.)

          11.13.  INSURANCE.

(No change.)

          11.14.  PUBLICITY.

(No change.)

          11.15.  ENTIRE AGREEMENT.

Insert at the beginning of Section 11.15,  "This Addendum I shall have no effect
whatsoever on the agreement between WebMD and ChannelHealth."

          11.16.  NO THIRD PARTY BENEFICIARIES.

(No change.)

          11.17.  NON-HIRE.

(No change.)

          11.18.  STOCK OPTION AGREEMENT.
--------------------------------------------------------------------------------
                                  Page 7 of 16
Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

Delete Section 11.18 in its entirety.

          11.19.  PAYMENTS.

Insert the following additional section:

          11.19.  Payments.

          Not later than [**],  WebMD shall pay IDX the sum of $[**] in full and
          final  satisfaction  of all amounts due on account under the Agreement
          for the period from [**]. IDX shall pay WebMD the sum of $[**] in full
          and final  satisfaction  for all claims for amounts due on account for
          the period from [**].  For  charges  incurred  after such  dates,  the
          parties shall make payments according to the rates and schedule as set
          forth in the Agreement and as modified by Addendum I.

          11.20.  MUTUAL RELEASES.

Insert the following additional section:

          11.20 Mutual releases.

          (a) By IDX. IDX and its  Affiliates  hereby fully and forever  release
          WebMD, its Affiliates,  officers,  agents, directors and employees and
          officers, directors and employees of each Affiliate of WebMD, from all
          actions,  causes of action,  suits,  debts,  dues,  expenses,  sums of
          money, accounts, costs, reckonings,  interests,  deficiencies,  bonds,
          bills, specialties,  covenants,  commission contracts,  controversies,
          agreements,   promises,  variances,  trespasses,  damages,  judgments,
          executions,  claims,  and  demands  whatsoever  in law,  admiralty  or
          equity, against WebMD and its Affiliates ("IDX Claims"), which IDX and
          its  Affiliates  (or any of them) ever had, now have or hereafter can,
          shall or may have for, upon or by reason of any manner,  cause, thing,
          claim,  contention  or  allegation  whatsoever  that arose or occurred
          prior to the Effective Date of the addendum based upon, in whole or in
          part,  this  Agreement,  other than IDX Claims arising on or after the
          Effective  Date of Addendum I due to a breach by WebMD on or after the
          Effective Date of Addendum I.

          (b) By WebMD.  WebMD and its Affiliates  fully and forever release IDX
          and its  Affiliates,  officers,  agents,  directors  and employees and
          officers,  directors and  employees of each  Affiliate of IDX from all
          actions,  causes of action,  suits,  debts,  dues,  expenses,  sums of
          money, accounts, costs, reckonings,  interests,  deficiencies,  bonds,
          bills, specialties,  covenants,  commission contracts,  controversies,
          agreements,   promises,  variances,  trespasses,  damages,  judgments,
          executions,  claims,  and  demands  whatsoever  in law,  admiralty  or
          equity,  against IDX and its Affiliates ("WebMD Claims"),  which WebMD
          and its  Affiliates  (or any of them) ever had,  now have or hereafter
          can,  shall or may have for,  upon or by reason of any manner,  cause,
          thing,  claim,  contention  or  allegation  whatsoever  that  arose or
          occurred  prior to the  Effective  Date of Addendum I based  upon,  in
          whole or in part this Agreement, other than WebMD Claims arising on or
          after the  Effective  Date of  Addendum I due to a breach by IDX on or
          after the Effective Date of Addendum I.

12.       AMENDED AND RESTATED GLOSSARY
--------------------------------------------------------------------------------
Delete the  Glossary  set forth in Section  12 of the  Agreement  and insert the
following in lieu thereof.

         Amended and Restated Glossary

         "Affiliate"  has the meaning set forth in rule 12(b) of the  Securities
         Act of  1934.  For the  purposes  of  calculating  fees due to IDX from
         WebMD,  "Affiliates"  shall not  include  any  clearinghouse  or claims
         processing  service to which WebMD pays fees,  provided  WebMD does not
         Control,  is not  Controlled  by, or is not under common  Control with,
         such  clearinghouse  or claims  processing  service.  Affiliates of IDX
         shall not include Allscripts Healthcare Solutions,  Inc., Channelhealth
         Incorporated, or any entity Controlled by, Controlling, or under common
         Control with either of them.

          "Confidential Information" means (i) any data or information,  oral or
         written,  that relates to any party's business practices or activities;
         (ii) any information,  ideas, know-how, trade secrets,  specifications,
         designs,  plans,  flow-charts,   drawings,  research  and  development,
         processes,  procedures  and market  research;  (iii) any source code or
         executable code versions of software;  and (iv) any other  information,
         regardless  of  form,  for  which  a  party  would  have  a  reasonable
         expectation of  confidentiality.  Confidential  Information  shall also
         include the terms and conditions of this Agreement.
--------------------------------------------------------------------------------
                                  Page 8 of 16
Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

          "Control,"  "Controlled  by,"  "Controlling"  and similar  terms shall
          mean, with respect to an Entity:

          (i) The  acquisition (other than from the Entity under  consideration)
          by any  person,  entity or  "group",  within  the  meaning  of Section
          13(d)(3)  or  14(d)(2)  of the  Securities  Exchange  Act of 1934 (the
          "Exchange Act"), of beneficial ownership,  (within the meaning of Rule
          13d-3  promulgated  under the Exchange  Act) of fifty percent (50%) or
          more of either  the then  outstanding  shares  of common  stock or the
          combined  voting  power  of  the  Entity's  then  outstanding   voting
          securities entitled to vote generally in the election of directors; or

          (ii)Approval  by the  stockholders  of the party of a  reorganization,
          merger, consolidation, in each case, with respect to which persons who
          were  the  stockholders  of  the  party   immediately  prior  to  such
          reorganization,   merger   or   consolidation   do  not,   immediately
          thereafter,  own more than fifty percent (50%) of the combined  voting
          power  entitled to vote  generally in the election of directors of the
          reorganized,  merged or consolidated  Entity's then outstanding voting
          securities,  or a liquidation  or  dissolution of the Entity or of the
          sale of all or substantially all of the assets of the Entity.

          "Current Volume" means the volume of  Participating  Payer Batch Claim
          Transactions  submitted  during  the  month  of  April  2001,  whether
          submitted  via the  IDX  Gateway  or  otherwise  from an IDX  Practice
          Management System, determined as set forth in Section 5 of the Payment
          Schedule attached to Addendum I.

          "De-Identified  Data"  means  data  from  which  information  has been
          removed as required by law (including without limitation HIPAA), or if
          no law is applicable,  removed according to a commercially  recognized
          standard,  so  that  what  remains  of  such  data  cannot  be used to
          personally or otherwise  identify the individual or entity that is the
          subject of such data (such as names, social security numbers, employer
          I.D. numbers, addresses, and other identifying data).

          "Effective  Date" means June 6, 2000 with respect to the Agreement and
          March 31, 2001 with respect to Addendum I.

          "Entity" means any legal or natural person and any Affiliate  thereof.

          "Exclusive  Period"  means the period from the date of this Addendum I
          until [**].

          "Featured" shall be a term that applies only with respect to Financial
          EDI Transactions that are for Participating Payers and shall mean with
          respect to promotion and  integration of WebMD's  related  transaction
          services,  the  obligations  of IDX to perform as set forth in Section
          1.1(b) of Addendum I.

          "Featuring Conditions" means Sections 4.7(a)(i),(ii), and (iii) of the
          Agreement as amended by Addendum I.

          "Featuring  Period"  means  the  period  from the date of  Addendum  I
          through [**].

          "Financial   EDI   Transactions"   means  the   following  of  WebMD's
          financial-related,  medical  electronic  transactions  accomplished by
          electronic  data  interchange  or the  Internet:  medical  claims  and
          encounters, UB-92 claims originating from providers but not hospitals,
          electronic  remittance  advice,  eligibility,  referrals,  and  claims
          status updates.

          "HIPAA" means the Health Insurance  Portability and Accountability Act
          of 1996, as amended.

          "IDX"  means IDX  Systems  Corporation,  a Vermont  corporation,  with
          principal offices at 40 IDX Drive, South Burlington, Vermont 05403.

          "IDX  Gateway"  means a system  provided  by IDX for  aggregating  and
          switching electronic data interchange transactions.

          "Intellectual Property" means patents, copyrights, trademarks, service
          marks,  trade names,  trade dress,  domain names, Web sites,  logos or
          other proprietary rights.

          "Interfaces" means data maps,  software,  protocols,  translations and
          other  functionality  that facilitate the organization and transfer of
          data.

          "Marks" means trademarks,  service marks,  trade names, logos and such
          other business identifiers.

          "Non-Participating  Payer" means any Payer that is not a Participating
          Payer.

          "Non-Participating  Payer Batch Claim  Transaction"  means  electronic
          batch claim  transactions  (excluding  UB-92 claims  originating  from
--------------------------------------------------------------------------------
                                  Page 9 of 16
hospitals  as  distinguished  from  providers)  originating  from  IDX
          Practice Management System and sent via the IDX Gatewayto WebMD or any
          Affiliates of WebMD for submission in batches and not in Real Time for
          processing by or for a Non-Participating Payer.

          "Non-Participating  Payer  Real  Time  Transaction"  means  electronic
          non-batch   (Real-Time)    eligibility   and   referrals   transaction
          originating from IDX Practice  Management  Systems and that is sent to
          WebMD or any Affiliate of WebMD via the IDX Gateway for  processing by
          or for a Non-Participating Payer.

          "Participating  Payer" means any Payer that pays any  consideration to
          WebMD for  transactions,  regardless of the method or form of payment.
          However,  for the purpose of calculating fees due to IDX from WebMD on
          Transactions with Participating  Payers, such term shall not include a
          clearinghouse  or claims  processing  service to which WebMD pays fees
          and which is not an Affiliate of WebMD.

          "Participating  Payer Batch Claim  Transaction" means electronic batch
          claim transactions  (excluding UB-92 claims originating from hospitals
          as  distinguished  from  providers)   originating  from  IDX  Practice
          Management  Systems and sent to WebMD or any  Affiliates  of WebMD for
          submission in batches and not in real time to Participating Payers for
          processing  by or for  such  Participating  Payers.  However,  for the
          purpose of calculating fees due to IDX from WebMD on Transactions with
          Participating  Payers,  "Participating  Payer Batch Claim Transaction"
          shall not include  transactions  submitted to WebMD by a clearinghouse
          or claims processing service to which WebMD pays fees and which is not
          an Affiliate of WebMD.

          "Participating Payer Real Time Transaction" means electronic non-batch
          (Real-Time) eligibility and referrals transaction originating from IDX
          Practice Management Systems and that is sent to WebMD or any Affiliate
          of WebMD for processing by or for a Participating Payer.  However, for
          the purpose of calculating  fees due to IDX from WebMD on Transactions
          with Participating Payers, "Participating Payer Real Time Transaction"
          shall not include  transactions  submitted to WebMD by a clearinghouse
          or claims processing service to which WebMD pays fees and which is not
          an Affiliate of WebMD.

          "Payer" means any entity,  such as an insurance company,  managed care
          organization,  fiscal intermediary,  fiscal carrier,  fiscal agent, or
          information  services,  that pays claims  resulting from EDI Financial
          Transactions.

          "Payment  Schedule"  means the new payment  schedule  attached to this
          Addendum I in lieu of the Payment Schedule attached to the Agreement.

          "Practice  Management  System"  shall  mean any  software  application
          expressly  designed  and/or marketed by IDX, or any of its Affiliates,
          to automate the business  processes  of physician  billing,  physician
          scheduling,  managed care contract  administration,  hospital clinical
          practice,    physician    clinical    practice,    hospital    patient
          administration,  or hospital billing,  including by way of example and
          not in  limitation,  as embodied in the  products  currently  marketed
          under the trademarks "GPMS" and "IDXtendR."

          "Real-Time" means not in a batch mode.

          "Term"  means  collectively  the Initial Term and each Renewal Term as
          defined in Sections 4.1 and 4.2 of the Agreement.

          "WebMD"  means WebMD  Corporation,  a Delaware  corporation  (formerly
          known as  Healtheon/WebMD  Corporation)  with principal offices at 669
          River   Drive,   Center  Two,   Elmwood   Park,   New  Jersey   07407.
--------------------------------------------------------------------------------
                                 Page 10 of 16
IN WITNESS  WHEREOF , the  parties  hereto have executed this Agreement.

IDX SYSTEMS CORPORATION

By: /S/ RICHARD E. TARRANT
    ------------------------------------------
         (authorized signature)

Name: Richard E. Tarrant
      ----------------------------------------
         (printed)

Title: C.E.O.
       ---------------------------------------

Date:  3/30/01
      ----------------------------------------

WebMD CORPORATION

By: /S/ MICHAEL B GLICK
    ------------------------------------------
         (authorized signature)

Name: Michael B. Glick
      ----------------------------------------
         (printed)

Title: Senior Vice President - Legal
       ---------------------------------------

Date:  3/30/01
      ----------------------------------------

--------------------------------------------------------------------------------
                                 Page 11 of 16
Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

                                PAYMENT SCHEDULE

1.   PARTICIPATING PAYER BATCH CLAIM TRANSACTION FEES.

(a)       PREFERRED RATE. For Participating  Payer Batch Claim  Transactions
          submitted  prior to [**],  [**],  the fees payable by WebMD to IDX for
          every such  claim  shall be [**] the fees  collected  by webmd and all
          Affiliates of WebMD from Participating  Payers for such claims or (ii)
          $[**]. This shall be referred to as the "Preferred Rate."

(b)       ORDINARY RATE.  From and after [**], the applicable  rate for fees
          payable by WebMD for  Participating  Payer  Batch  Claim  Transactions
          shall be calculated  pursuant to Table I below. This shall be referred
          to as the "Ordinary Rate."

(c)       ADJUSTMENT.  IDX's claims  volume for  Participating  Payer Batch
          Claim  Transactions shall be measured for the month of [**]. If during
          such month,  IDX's claims volume for such  transactions  shall be less
          than [**] times the Current Volume, then for the [**] period, the fees
          payable  to  IDX  by  WebMD  for  Participating   Payers  Batch  Claim
          Transactions  shall not be calculated at the Preferred Rate, but shall
          be calculated at the Ordinary Rate.  However,  the preceding  sentence
          shall not apply if the volume is greater than [**]transactions in such
          month. If for any month prior to [**], IDX's claim volume is such that
          it would  receive  greater fees at the Ordinary  Rate,  then that rate
          shall apply for such month.

(d)       CERTAIN MINIMUM RATE. Notwithstanding the foregoing, for any month
          from and after [**] during the term of the Agreement  that IDX's total
          monthly  volume of  Participating  Payer Batch Claim  Transactions  is
          equal to or exceeds [**] times the Current  Volume,  or in any case if
          such volume  exceeds  [**]  million  claims,  then the fees payable by
          WebMD for such transactions  during such month shall be the greater of
          (i) the Preferred Rate and (ii) the Ordinary Rate.

2.   OTHER PARTICIPATING PAYER TRANSACTIONS.

     Notwithstanding  anything to the contrary herein, WebMD shall not be liable
     to make any  payments  to IDX  pursuant  to this  Section 2 of the  Payment
     Schedule [**]submits [**].

(a)       ELIGIBILITY  AND REFERRAL  TRANSACTIONS.  For every  Participating
          Payer  Real  Time  Transaction,  WebMD  shall pay IDX [**] of the fees
          collected  by WebMD and all  Affiliates  of WebMD  from  Participating
          Payers for such transaction.

(b)       ELECTRONIC REMITTANCE TRANSACTIONS. In recognition of the evolving
          nature of  remittance  transactions,  the  parties  shall  attempt  to
          negotiate fees for remittances  involving  Participating Payers. There
          shall be no obligations  with respect to such  transactions  hereunder
          until and unless such fees are negotiated.

3.    NON-PARTICIPATING PAYER TRANSACTIONS FEES.

(a)       BATCH   CLAIMS   AND   REAL   TIME   TRANSACTIONS.   For   every
          Non-Participating Payer Batch Claim Transaction, and Non-Participating
          Payer Real Time  Transaction,  IDX shall pay WebMD the  greater of (x)
          [**] of fees collected by IDX [**] or (y) (i) $[**],  per  transaction
          in which the aggregate  amount of such  transactions  are less than or
          equal to [**]  million;  (ii)  $[**]  per  transaction  in  which  the
          aggregate  amount of such  transactions are less than or equal to [**]
          million;  or (iii)  $[**]  per  transaction  in any month in which the
          aggregate  amount of such  transactions are greater than [**] million.
          Notwithstanding the foregoing,  for all such transactions submitted by
          IDX  during  the  period  from the date of  Addendum  I through  [**],
          regardless  of the  volume of such  transactions,  IDX shall pay WebMD
          $[**] per transaction.

(b)       CERTAIN  ADJUSTMENTS.  The foregoing fee  arrangement set forth in
          Section  3(a)  of  this  Payment   Schedule  shall  apply  to  such  a
          transaction  when  [**],  but in such  event , IDX shall  [**] for all
          amounts  paid  [**],  up to the  amount  otherwise  payable  to  WebMD
          pursuant  to Section  3(a) of this  Payment  Schedule,  and any amount
          payable  in excess of such  amount  [**]  pursuant  to Table 1. To the
          extent that after the date hereof WebMD  obtains an  agreement  with a
          Non-commercial  Payer (defined  below) to submit claims to [**],  then
          for purposes of Section 3 of this Payment Schedule,  such fee shall be
          treated as set forth in the foregoing sentence. "Non-commercial Payer"
          means a Payer of claims under government  programs and Blue Cross/Blue
          Shield.
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                Exchange Commission. Asterisks denote omissions.

(c)      ELECTRONIC  REMITTANCE  TRANSACTIONS.  In  recognition  of the evolving
         nature  of  remittance  transactions,  the  parties  shall  attempt  to
         negotiate  fees for  remittances  involving  Non-Participating  Payers.
         There  shall  be no  obligations  with  respect  to  such  transactions
         hereunder until and unless such fees are negotiated.

4.       PAYMENTS.

(a)      MONTHLY PAYMENTS. All payment shall be made monthly in arrears, except
         as provided below.

(b)      MONTHLY STATEMENTS.  Not later than the [**] day of each calendar month
         of the Term,  WebMD  shall  send to IDX and IDX  shall  send to WebMD a
         written  statement  of the actual  activity  and fees owed with respect
         thereto during the prior calendar month,  signed by an officer of WebMD
         or an officer of IDX, as the case may be, determined in accordance with
         the terms hereof together with the data and  assumptions,  if any, used
         to calculate the fees owed by WebMD to IDX or IDX to WebMD, as the case
         may be.

(c)      PAYMENTS. Not later than the [**] day of each calendar month commencing
         with the calendar  month of the Effective Date of Addendum I, WebMD pay
         all amounts due to IDX for the prior  calendar  month and IDX shall pay
         all amounts due to WebMD for the prior calendar month.

(d)      OBJECTION;  ESTIMATED  PAYMENTS.  If either party objects in writing to
         the  amounts  claimed  payable  as set  forth  in a  monthly  statement
         provided  by  the  other  party,  then  such  other  party  shall  make
         nevertheless  make an  estimated  payment not later than the end of the
         month in which the  objection is made,  which  estimated  payment shall
         include an amount on account  for  transactions  that shall be equal to
         the  average  daily  rate  for such  transactions  as  determined  with
         reference  to the  previous  Monthly  Statement,  times  the  number of
         business days during the month in dispute.

(e)      DISPUTE RESOLUTION.  The parties shall meet and confer to resolve any
         payment disputes within 30 days thereafter.  Any overpayment  shall be
         credited to the next month's payment.

5.       DETERMINATION OF CLAIMS ORIGINATING FROM AN IDX PRACTICE MANAGEMENT
         SYSTEM.

(a)      Within [**]days from the date hereof [**] with the following additional
         information: [**].  This list shall be Confidential Information.

(b)      In the Envoy  system the Tax ID number is used to create the  Submitter
         ID Number.  WebMD  shall  confirm  how the other  WebMD  clearinghouses
         assign Submitter IDs.

(c)      [**] an Envoy Submitter Number or other WebMD clearinghouse Submitter
         ID Number. WebMD shall cooperate with IDX [**] is in [**] in cases
         [**].

(d)      WebMD  shall  [**]  for  whom it can  identify  a  WebMD  clearinghouse
         Submitter  ID Number  except (a) for and only to the  extent  that [**]
         that is already  associated with a clearinghouse that is [**] through a
         Submitter  ID Number;  or (b) for and to the  extent  that [**] [**] is
         submitting  claims  through a different  vendor (such as POMIS  vendor,
         claims  aggregator;  repricer  or other  entity)  that is  receiving  a
         payment [**]. A Parent  Account Number shall be assigned [**] and shall
         be associated with each account [**].

(e)      Upon the request of IDX, WebMD shall provide IDX [**].

(f)      On a monthly  basis WebMD shall  provide a report to IDX (the  "Monthly
         Activity  Report") showing the claims activity for each submitter [**].
         The  payments  to IDX  from  WebMD  and  from  IDX to  WebMD  shall  be
         determined by this Monthly  Activity  Report.  IDX shall have [**] days
         from the  receipt of each  Monthly  Activity  Report to  challenge  the
         reported  activity for any  submitter on such report or the omission of
         any submitter from such report.

(g)      If  requested  by a party,  the parties  shall  repeat the process set
         forth herein to validate volumes from time to time.
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Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

                   Payment Schedule - Table 1 (Ordinary Rate)

                            TABLE 1 (ORDINARY RATE)

   WebMD shall pay IDX the portion of fees set forth in the column headed "%
   of Fees"*:

                PER CLAIM VOLUME REBATE                 % OF FEES

                  FROM           TO

                  [**]           [**]                   [**]%
                  [**]           [**]                   [**]%
                  [**]           [**]                   [**]%
                  [**]           [**]                   [**]%
                  [**]           [**]                   [**]%

* Fees do not include fees generated with the intervention of another (non-
WebMD Affiliate) clearinghouse or claims processing services to which WebMD
pays fees.

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                                 Page 14 of 16
Confidential Materials omitted and filed separately with the Securities and
                Exchange Commission. Asterisks denote omissions.

                  FINANCIAL TRANSACTIONS SERVICE LEVEL SCHEDULE

This Schedule  describes the minimum service levels necessary for support of EDI
Financial  Transactions  by WebMD (TSD).

ISSUE TYPES
--------------------------------------------------------------------------------
Each issue reported to the WebMD Support Team is subject to the following
turn-around  times stated below. WebMD must meet these turn-around times in
[**]% of all cases.

                TYPE OF ISSUE           TURN-AROUND TIME
                -------------           -----------------

                Question                [**] business days

                Problem                 [**] business days1

                Critical                [**] business day average

                Request                 Evaluated on a case-by-case basis

QUESTION
         A QUESTION is any inquiry  about the basic  functioning  of the service
         that is not answered or documented in a manual.

PROBLEM
         A PROBLEM  is any  situation  within  the  control  of WebMD  where the
         service  is not in  accordance  with  WebMD's  documentation  and whose
         solution  may require data  modification  or software  modification  by
         WebMD.   Problems  include  enrollment  issues,   report  availability,
         inappropriate claim rejections, any payer-specific problem, etc.

CRITICAL
         These are  certain  issues  within  the  control  of WebMD  that  WebMD
         considers  critical  and  gives  immediate  attention  to as  they  are
         reported.  CRITICAL issues are "business stoppers" for the customer and
         are the cases that IDX  considers  a priority  for  eCommerce  Support.
         Critical issues include those that would disable all IDX customers from
         submitting claims to WebMD or WebMD is unable to submit all claim files
         of IDX  customers  to all  payers.

----------------------------
1 Where a problem can only reasonably be addressed through software
modification, that will be communicated within[**] days, and the problem
will be fixed in the next scheduled release or modification.

--------------------------------------------------------------------------------
                                 Page 15 of 16
REQUEST
         A REQUEST is a need for  additional service/setup  that is part of the
         standard  implementation and support cycle.  An  example  would be
         adding  new  providers  or groups in the enrollment process.

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                                 Page 16 of 16