<PAGE>

AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON DECEMBER 30, 1999.
                           REGISTRATION NO. 33-_______

                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

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

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

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

                         MAGELLAN HEALTH SERVICES, INC.
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

                DELAWARE                               58-1076937
     (STATE OR OTHER JURISDICTION OF      (I.R.S. EMPLOYER IDENTIFICATION NO.)
     INCORPORATION OR ORGANIZATION)

                           6950 COLUMBIA GATEWAY DRIVE
                            COLUMBIA, MARYLAND 21046
                    (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)

          MAGELLAN HEALTH SERVICES, INC. SUPPLEMENTAL ACCUMULATION PLAN
                            (FULL TITLE OF THE PLAN)

                              MARK S. DEMILIO, ESQ.
                  EXECUTIVE VICE PRESIDENT AND GENERAL COUNSEL
                         MAGELLAN HEALTH SERVICES, INC.
                          6950 COLUMBIA GATEWAY DRIVE
                            COLUMBIA, MARYLAND 21046
                                 (410) 953-1258
            (NAME, ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER,
                   INCLUDING AREA CODE, OF AGENT FOR SERVICE)

                                 ---------------
                         CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
                                             Proposed maximum    Proposed maximum
Title of securities         Amount to be      offering price     aggregate offering        Amount of
 To be registered           registered        per obligation         price(1)          registration fee
 ----------------           ----------        ---------------        ------            ----------------
<S>                         <C>              <C>                 <C>                   <C>
Deferred Compensation
Payment Obligations(2)      $6,000,000             100%             $6,000,000              $1,584
</TABLE>

----------
(1)  Estimated solely for the purposes of calculating the registration fee.
(2)  The deferred compensation payment obligations are unsecured obligations of
     Magellan Health Services, Inc. to pay deferred compensation in accordance
     with the terms of the Magellan Health Services, Inc. Supplemental
     Accumulation Plan.


<PAGE>


                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.   INCORPORATION OF DOCUMENTS BY REFERENCE.

         The following document filed by Magellan Health Services, Inc. (the
"Registrant") with the Securities and Exchange Commission (the "Commission") is
incorporated by reference and made a part hereof:

                  (a) The Registrant's Annual Report on Form 10-K for the year
ended September 30, 1999, filed with the Commission on December 27, 1999.

         All documents subsequently filed by the Registrant pursuant to Section
13(a), 13(c), 14 or 15(d) of the Exchange Act prior to the filing of a
post-effective amendment which indicates that all securities offered have been
sold or which deregisters all securities then remaining unsold shall be deemed
to be incorporated by reference into this Registration Statement and to be a
part hereof from the date of filing of such documents.

ITEM 4.   DESCRIPTION OF SECURITIES.

         Under the Magellan Health Services, Inc. Supplemental Accumulation Plan
(the "Plan"), the Registrant will provide eligible directors, management and
other highly-compensated employees the opportunity to defer a specified portion
of their compensation. The Plan is to be administered by one or more persons who
are designated as Administrators by the Registrant from time to time. The
obligations of the Registrant to pay the deferred compensation, as adjusted for
earnings, losses and expenses thereon in accordance with the terms of the Plan
(the "Deferred Compensation Payment Obligations"), are unsecured general
obligations of the Registrant and rank pari passu with other unsecured general
obligations of the Registrant. This Registration Statement covers $6,000,000 of
Deferred Compensation Payment Obligations.

         The Deferred Compensation Payment Obligations of each participant will
be an amount equal to (i) the amount deferred in accordance with the
participant's written deferral election under the Plan ("Compensation
Deferrals"); (ii) the Registrant's matching contributions ("Matching
Contributions"); and (iii) additional amounts that may be contributed by the
Registrant, in its discretion, for certain participants ("Discretionary
Contributions"), all as adjusted for earnings, losses and expenses attributable
thereto.

         Deferred Compensation Payment Obligations under the Plan shall be
indexed to, and earnings or losses will accrue thereon at rates equal to, the
investment returns of specified investment funds designated by the Plan
Administrator. From time to time during the life of the Plan the Plan
Administrator may change the investment funds available to participants under
the Plan. Prior to making any such changes, however, the Plan Administrator will
advise participants of the change and give participants the option to allocate
their Deferred Compensation Payment Obligations among the new investment funds.

                                      -2-
<PAGE>

         All Deferred Compensation Payment Obligations that relate to
Compensation Deferrals and earnings thereon are 100% vested at all times.
Obligations that relate to Matching Contributions and any earnings thereon vest
according to the vesting provisions of the Registrant's 401(k) Plan. Obligations
that relate to Discretionary Contributions and any earnings thereon vest on the
date that is two years after the date those contributions were made. A
participant's total Deferred Compensation Payment Obligations will also be fully
vested upon a change in control of the Registrant, the participant's involuntary
termination of employment without cause, death, or total and permanent
disability. A participant will forfeit 100% of his or her Matching Contributions
and Discretionary Contributions upon the termination of his or her employment by
the Registrant due to cause, as defined in the Plan, or if the participant
engages in competition while employed by the Registrant or within two years
after the termination of his or her employment.

         If the participant so elects before the beginning of any plan year,
then shortly after the end of that plan year an amount equal to the maximum
elective 401(k) contributions that the participant could make for that plan year
to the Registrant's 401(k) plan, as determined by the Administrator, will be
deducted from the participant's Compensation Deferrals made to this Plan during
that year and paid over to the Registrant's 401(k) plan as elective 401(k)
contributions made by the participant for that year. This feature allows the
participant to maximize his or her 401(k) plan contributions for that year.

         In limited circumstances of severe financial hardship, as defined in
the Plan, a participant may be permitted, in the discretion of the Plan
Administrator, to make a withdrawal from the Obligations attributable to his or
her vested Compensation Deferrals and Matching Contributions (before the date
those amounts are otherwise payable to the participant) of the amount that the
Administrator determines to be necessary to alleviate the hardship and that is
not available to the participant from other sources. The participant may also
elect in writing to make a nonscheduled withdrawal (at any time before the
amount otherwise becomes payable) of any amount from the Obligations
attributable to his or her vested Compensation Deferrals and Matching
Contributions, provided that 10% of the withdrawal amount shall be forfeited by
the participant and the participant's right to make Compensation Deferrals shall
be suspended until the end of the plan year following the plan year in which the
withdrawal is made.

         Generally, Obligations in an amount equal to each participant's
Compensation Deferrals and Matching Contributions, as adjusted for earnings,
losses and expenses, will be payable at the earlier of the date the
participant's employment with the Registrant terminates or a fixed date elected
by the participant as a part of his or her deferral election, but in no event
earlier than the date that is two years after the date the last of those
Compensation Deferrals was made. Amounts attributable to Discretionary
Contributions made by the Registrant for the participant's benefit become
payable at any date selected by the Administrator in the first calendar month
that is two years after the participant's employment by the Registrant has
terminated or, if later, at any payment date previously elected by the
participant. If no earlier payment date applies, the Obligations attributable to
the participant's Compensation Deferrals and Matching Contributions will be
payable when amounts attributable to the Discretionary Contributions made by the
Registrant for the participant become payable.

                                      -3-
<PAGE>

         If the amount available for distribution on any given payment date is
less than $50,000, then the entire amount shall be distributed to the
participant in one lump sum payment, regardless of the participant's election.
If the amount distributable on any given payment date equals or exceeds $50,000,
then the amount will be paid either in one lump sum payment or, if elected by
the participant as a part of his or her deferral election, in twenty or forty
quarterly payments. Under certain circumstances, a participant may elect to
further defer payments otherwise payable on a specified distribution date, but
that election must be made more than 12 months before the specified distribution
date and a participant may make an election to further defer those payments only
once.

         If the participant dies while employed by the registrant, all of his or
her Deferred Compensation Payment Obligations shall be paid to the participant's
beneficiary in a lump sum. If the participant dies after termination of his or
her employment with the Registrant, all of the participant's undistributed
vested Deferred Compensation Payment Obligations shall be paid to the
participant's beneficiary in one lump sum payment, except that amounts that were
being distributed to the participant in installment payments shall continue to
be paid in those installments unless the Registrant elects to accelerate those
payments.

         No amounts payable to participants or beneficiaries under the Plan
will, except as otherwise specifically provided by law, be subject in any matter
to anticipation, alienation, attachment, garnishment, sale, transfer, assignment
(either at law or in equity), levy, execution, pledge, encumbrance, charge or
any other legal or equitable process, and any attempt to do so will be void.
Notwithstanding the foregoing, however, participants may designate any person or
persons to receive such benefits as may be payable under the Plan upon or after
the participant's death. If no such beneficiary designation is made, or if no
beneficiary is living at the time of a participant's death, benefits will be
paid to the participant's spouse, if then living, but otherwise to the
participant's living descendants, if any, but, if none, to the participant's
estate.

         Deferred Compensation Payment Obligations are not subject to redemption
by the Registrant, in whole or in part, prior to the distribution dates selected
by the respective participants under the Plan. Notwithstanding the foregoing,
however, the Registrant has reserved the right to amend or terminate the Plan at
any time, provided that no amendment of the Plan shall deprive a participant or
a beneficiary of a right accrued under the Plan prior to the date of the
amendment.

ITEM 5.   INTERESTS OF NAMED EXPERTS AND COUNSEL.

         Not Applicable

ITEM 6.   INDEMNIFICATION OF DIRECTORS AND OFFICERS.

         The Registrant is a Delaware corporation. Section 145 of the Delaware
General Corporation Law (the "DGCL") provides that a Delaware corporation has
the power to indemnify its officers and directors in certain circumstances.

                                      -4-
<PAGE>

         Subsection (a) of Section 145 of the DGCL empowers a corporation to
indemnify any director or officer, or former director or officer, who was or is
a party or is threatened to be made a party to any threatened, pending or
completed action, suit or proceeding, whether civil, criminal, administrative or
investigative (other than an action by or in the right of the corporation) by
reason of his or her service as director, officer, employee or agent of the
corporation, or his or her service, at the corporation's request, as a director,
officer, employee or agent of another corporation or enterprise, against
expenses (including attorneys' fees), judgments, fines and amounts paid in
settlement actually and reasonably incurred in connection with such action, suit
or proceeding provided that such director or officer acted in good faith and in
a manner reasonably believed to be in or not opposed to the best interests of
the corporation, and, with respect to any criminal action or proceeding,
provided that such director or officer had no reasonable cause to believe his or
her conduct was unlawful.

         Subsection (b) of Section 145 empowers a corporation to indemnify any
director or officer, or former director or officer, who was or is a party or is
threatened to be made a party to any threatened, pending or completed action or
suit by or in the right of the corporation to procure a judgment in its favor by
reason of the fact that such person acted in any of the capacities set forth
above, against expenses (including attorneys' fees) actually and reasonably
incurred in connection with the defense or settlement of such action or suit
provided that such director or officer acted in good faith and in a manner he or
she reasonably believed to be in or not opposed to the best interests of the
corporation, except that no indemnification may be made in respect of any claim,
issue or matter as to which such director or officer shall have been adjudged to
be liable to the corporation unless and only to the extent that the Court of
Chancery or the court in which such action or suit was brought shall determine
upon application that, despite the adjudication of liability but in view of all
the circumstances of the case, such director or officer is fairly and reasonably
entitled to indemnity for such expenses which the court shall deem proper.

         Section 145 further provides that, to the extent a director or officer
of a corporation has been successful in the defense of any action, suit or
proceeding referred to in subsections (a) or (b) or in the defense of any claim,
issue or matter therein, he or she shall be indemnified against expenses
(including attorneys' fees) actually and reasonably incurred by him in
connection therewith; provided that indemnification provided for by Section 145
or granted pursuant thereto shall not be deemed exclusive of any other rights to
which the indemnified party may be entitled; and empowers the corporation to
purchase and maintain insurance on behalf of a director or officer of the
corporation against any liability asserted against him or her or incurred by him
or her in any such capacity or arising out of his or her status as such whether
or not the corporation would have the power to indemnify him or her against such
liabilities under Section 145.

         Article VII of the Bylaws of the Registrant provides in substance that
the Registrant shall indemnify directors and officers against all liability and
related expenses incurred in connection with the affairs of the Registrant if:
(a), in the case of actions not by or in the right of the Registrant, the
director or officer acted in good faith and in a manner he or she reasonably
believed to be in or not opposed to the best interests of the Registrant, and
(with respect to a criminal proceeding) had no reasonable cause to believe his
or her conduct was unlawful; and (b), in the case of actions by or in the right
of the Registrant, the director or officer acted in good

                                      -5-
<PAGE>

faith and in a manner he or she reasonably believed to be in or not opposed to
the best interests of the Registrant, provided that no indemnification shall be
made for a claim as to which the director or officer is adjudged liable for
negligence or misconduct unless (and only to the extent that) an appropriate
court determines that, in view of all the circumstances, such person is fairly
and reasonably entitled to indemnity.

         In addition, Section 102(b)(7) of the DGCL permits Delaware
corporations to include a provision in their certificates of incorporation
eliminating or limiting the personal liability of a director to the corporation
or its stockholders for monetary damages for breach of fiduciary duty as a
director, provided that such provisions shall not eliminate or limit the
liability of a director (i) for any breach of the director's duty of loyalty to
the corporation or its stockholders, (ii) for acts or omissions not in good
faith or that involve intentional misconduct or a knowing violation of law,
(iii) for unlawful payment of dividends or other unlawful distributions, or (iv)
for any transactions from which the director derived an improper personal
benefit. Article Twelve of the Registrant's Restated Certificate of
Incorporation contains such a provision.

         The Registrant maintains Directors' and Officers' liability insurance
with various insurance providers.

ITEM 7.   EXEMPTION FROM REGISTRATION CLAIMED.

         Not Applicable

ITEM 8.   EXHIBITS.

        Exhibit No.  Description of Exhibit
        -----------  ----------------------

            5        Opinion of Miles & Stockbridge P.C.

            23       Consent of Experts (the consent of counsel is included in
                     Exhibit 5).

ITEM 9.   UNDERTAKINGS.

         (a) The undersigned registrant hereby undertakes:

                  (1) To file, during any period in which offers or sales are
being made, a post-effective amendment to this registration statement:

                           (i) To include any prospectus required by Section
10(a)(3) of the Securities Act of 1933;

                           (ii) To reflect in the prospectus any facts or events
arising after the effective date of the registration statement (or the most
recent post-effective amendment thereof) which, individually or in the
aggregate, represent a fundamental change in the information set forth in the
registration statement; and

                                      -6-
<PAGE>

                           (iii) To include any material information with
respect to the plan of distribution not previously disclosed in the registration
statement or any material change to such information in the registration
statement;

                  Provided, however, that subparagraphs (1)(i) and (1)(ii) do
not apply if the information required to be included in a post-effective
amendment by those paragraphs is contained in periodic reports filed by the
registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange
Act of 1934 that are incorporated by reference in the registration statement.

                  (2) That, for the purpose of determining any liability under
the Securities Act of 1933, each such post-effective amendment shall be deemed
to be a new registration statement relating to the securities offered therein,
and the offering of such securities at that time shall be deemed to be the
initial bona fide offering thereof.

                  (3) To remove from registration by means of a post-effective
amendment any of the securities being registered which remain unsold at the
termination of the offering.

         (b) The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Securities Exchange Act of 1934 (and, where applicable, each filing of an
employee benefit plan's annual report pursuant to Section 15(d) of the
Securities Exchange Act of 1934) that is incorporated by reference in the
registration statement shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

         (c) Insofar as indemnification for liabilities arising under the
Securities Act of 1933 may be permitted to directors, officers and controlling
persons of the registrant pursuant to the foregoing provisions, or otherwise,
the registrant has been advised that in the opinion of the Securities and
Exchange Commission such indemnification is against public policy as expressed
in the Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
registrant of expenses incurred or paid by a director, officer or controlling
person of the registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Act and will
be governed by the final adjudication of such issue.

                                      -7-
<PAGE>


                                   SIGNATURES

         Pursuant to the requirements of the Securities Act, the registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Columbia, State of Maryland, on December 30, 1999.

                                           Magellan Health Services, Inc.

                                           By: /s/ Mark S. Demilio
                                               -------------------------------
                                                Mark S. Demilio
                                                Executive Vice President and
                                                General Counsel

         KNOW ALL MEN BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Clifford W. Donnelly and Mark S. Demilio
and each of them, his or her true and lawful attorneys-in-fact and agents, with
full power of substitution and resubstitution, for him or her and in his or her
name, place and stead, in any and all capacities, to sign any and all amendments
to this registration statement, and to file the same, with all exhibits thereto,
and other documents in connection therewith, with the Securities and Exchange
Commission, granting unto said attorneys-in-fact and agents full power and
authority to do and perform each and every act and thing requisite and necessary
to be done in and about the premises, as fully to all intents and purposes as he
or she might or could do in person, hereby ratifying and confirming all that
said attorneys-in-fact and agents, or their substitute or substitutes, may
lawfully do or cause to be done by virtue hereof.

         Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed by the following persons in the
capacities and on the dates indicated.

Signature                     Title                             Date
---------                     -----                             ----

/s/ HENRY T. HARBIN           President, Chief Executive      December 30, 1999
--------------------------    Officer and Director
Henry T. Harbin, M.D.

/s/ CLIFFORD W. DONNELLY      Executive Vice President        December 30, 1999
--------------------------    and Chief Financial Officer
Clifford W. Donnelly


/s/ THOMAS C. HOFMEISTER      Senior Vice President and       December 30, 1999
--------------------------    Chief Accounting Officer
Thomas C. Hofmeister

                              Director                        December __, 1999
--------------------------
David Bonderman

/s/ JONATHAN J. COSLET        Director                        December 30, 1999
--------------------------
Jonathan J. Coslet

                                      -8-
<PAGE>


Signature                     Title                           Date
---------                     -----                           ----

/s/ G. FRED DIBONA, JR.       Director                        December 30, 1999
--------------------------
G. Fred DiBona, Jr.


                              Director                        December __, 1999
--------------------------
Andre C. Dimitriadis

/s/ A.D. FRAZIER, JR.         Director                        December 30, 1999
--------------------------
A. D. Frazier, Jr.

/s/ GERALD L. MCMANIS         Director                        December 30, 1999
--------------------------
Gerald L. McManis

                              Director                        December __, 1999
--------------------------
Daniel S. Messina

/s/ ROBERT W. MILLER          Director                        December 30, 1999
--------------------------
Robert W. Miller

                              Director                        December __, 1999
--------------------------
Darla D. Moore

/s/ JEFFREY A. SONNENFELD     Director                        December 30, 1999
--------------------------
Jeffrey A. Sonnenfeld

/s/ JAMES B. WILLIAMS         Director                        December 30, 1999
--------------------------
James B. Williams

                                      -9-
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 26626}]
{"company-data": {"conformed-name": "MAGELLAN HEALTH SERVICES INC", "cik": "0000019411", "assigned-sic": "8060", "irs-number": "581076937", "state-of-incorporation": "DE", "fiscal-year-end": "0930"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-93911", "film-number": "99784089"}, "business-address": {"street1": "6950 COLUMBIA GATEWAY", "street2": "STE 400", "city": "COLUMBIA", "state": "MD", "zip": "21046", "phone": "4109531000"}, "former-company": {"former-conformed-name": "CHARTER MEDICAL CORP", "date-changed": "19920703"}}
AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON DECEMBER 30, 1999.
                           REGISTRATION NO. 33-_______

                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

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

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

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

                         MAGELLAN HEALTH SERVICES, INC.
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

                DELAWARE                               58-1076937
     (STATE OR OTHER JURISDICTION OF      (I.R.S. EMPLOYER IDENTIFICATION NO.)
     INCORPORATION OR ORGANIZATION)

                           6950 COLUMBIA GATEWAY DRIVE
                            COLUMBIA, MARYLAND 21046
                    (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)

          MAGELLAN HEALTH SERVICES, INC. SUPPLEMENTAL ACCUMULATION PLAN
                            (FULL TITLE OF THE PLAN)

                              MARK S. DEMILIO, ESQ.
                  EXECUTIVE VICE PRESIDENT AND GENERAL COUNSEL
                         MAGELLAN HEALTH SERVICES, INC.
                          6950 COLUMBIA GATEWAY DRIVE
                            COLUMBIA, MARYLAND 21046
                                 (410) 953-1258
            (NAME, ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER,
                   INCLUDING AREA CODE, OF AGENT FOR SERVICE)

                                 ---------------
                         CALCULATION OF REGISTRATION FEE
Proposed maximum    Proposed maximum
Title of securities         Amount to be      offering price     aggregate offering        Amount of
 To be registered           registered        per obligation         price(1)          registration fee
 ----------------           ----------        ---------------        ------            ----------------
Deferred Compensation
Payment Obligations(2)      $6,000,000             100%             $6,000,000              $1,584
----------
(1)  Estimated solely for the purposes of calculating the registration fee.
(2)  The deferred compensation payment obligations are unsecured obligations of
     Magellan Health Services, Inc. to pay deferred compensation in accordance
     with the terms of the Magellan Health Services, Inc. Supplemental
     Accumulation Plan.
PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.   INCORPORATION OF DOCUMENTS BY REFERENCE.

         The following document filed by Magellan Health Services, Inc. (the
"Registrant") with the Securities and Exchange Commission (the "Commission") is
incorporated by reference and made a part hereof:

                  (a) The Registrant's Annual Report on Form 10-K for the year
ended September 30, 1999, filed with the Commission on December 27, 1999.

         All documents subsequently filed by the Registrant pursuant to Section
13(a), 13(c), 14 or 15(d) of the Exchange Act prior to the filing of a
post-effective amendment which indicates that all securities offered have been
sold or which deregisters all securities then remaining unsold shall be deemed
to be incorporated by reference into this Registration Statement and to be a
part hereof from the date of filing of such documents.

ITEM 4.   DESCRIPTION OF SECURITIES.

         Under the Magellan Health Services, Inc. Supplemental Accumulation Plan
(the "Plan"), the Registrant will provide eligible directors, management and
other highly-compensated employees the opportunity to defer a specified portion
of their compensation. The Plan is to be administered by one or more persons who
are designated as Administrators by the Registrant from time to time. The
obligations of the Registrant to pay the deferred compensation, as adjusted for
earnings, losses and expenses thereon in accordance with the terms of the Plan
(the "Deferred Compensation Payment Obligations"), are unsecured general
obligations of the Registrant and rank pari passu with other unsecured general
obligations of the Registrant. This Registration Statement covers $6,000,000 of
Deferred Compensation Payment Obligations.

         The Deferred Compensation Payment Obligations of each participant will
be an amount equal to (i) the amount deferred in accordance with the
participant's written deferral election under the Plan ("Compensation
Deferrals"); (ii) the Registrant's matching contributions ("Matching
Contributions"); and (iii) additional amounts that may be contributed by the
Registrant, in its discretion, for certain participants ("Discretionary
Contributions"), all as adjusted for earnings, losses and expenses attributable
thereto.

         Deferred Compensation Payment Obligations under the Plan shall be
indexed to, and earnings or losses will accrue thereon at rates equal to, the
investment returns of specified investment funds designated by the Plan
Administrator. From time to time during the life of the Plan the Plan
Administrator may change the investment funds available to participants under
the Plan. Prior to making any such changes, however, the Plan Administrator will
advise participants of the change and give participants the option to allocate
their Deferred Compensation Payment Obligations among the new investment funds.

                                      -2-
All Deferred Compensation Payment Obligations that relate to
Compensation Deferrals and earnings thereon are 100% vested at all times.
Obligations that relate to Matching Contributions and any earnings thereon vest
according to the vesting provisions of the Registrant's 401(k) Plan. Obligations
that relate to Discretionary Contributions and any earnings thereon vest on the
date that is two years after the date those contributions were made. A
participant's total Deferred Compensation Payment Obligations will also be fully
vested upon a change in control of the Registrant, the participant's involuntary
termination of employment without cause, death, or total and permanent
disability. A participant will forfeit 100% of his or her Matching Contributions
and Discretionary Contributions upon the termination of his or her employment by
the Registrant due to cause, as defined in the Plan, or if the participant
engages in competition while employed by the Registrant or within two years
after the termination of his or her employment.

         If the participant so elects before the beginning of any plan year,
then shortly after the end of that plan year an amount equal to the maximum
elective 401(k) contributions that the participant could make for that plan year
to the Registrant's 401(k) plan, as determined by the Administrator, will be
deducted from the participant's Compensation Deferrals made to this Plan during
that year and paid over to the Registrant's 401(k) plan as elective 401(k)
contributions made by the participant for that year. This feature allows the
participant to maximize his or her 401(k) plan contributions for that year.

         In limited circumstances of severe financial hardship, as defined in
the Plan, a participant may be permitted, in the discretion of the Plan
Administrator, to make a withdrawal from the Obligations attributable to his or
her vested Compensation Deferrals and Matching Contributions (before the date
those amounts are otherwise payable to the participant) of the amount that the
Administrator determines to be necessary to alleviate the hardship and that is
not available to the participant from other sources. The participant may also
elect in writing to make a nonscheduled withdrawal (at any time before the
amount otherwise becomes payable) of any amount from the Obligations
attributable to his or her vested Compensation Deferrals and Matching
Contributions, provided that 10% of the withdrawal amount shall be forfeited by
the participant and the participant's right to make Compensation Deferrals shall
be suspended until the end of the plan year following the plan year in which the
withdrawal is made.

         Generally, Obligations in an amount equal to each participant's
Compensation Deferrals and Matching Contributions, as adjusted for earnings,
losses and expenses, will be payable at the earlier of the date the
participant's employment with the Registrant terminates or a fixed date elected
by the participant as a part of his or her deferral election, but in no event
earlier than the date that is two years after the date the last of those
Compensation Deferrals was made. Amounts attributable to Discretionary
Contributions made by the Registrant for the participant's benefit become
payable at any date selected by the Administrator in the first calendar month
that is two years after the participant's employment by the Registrant has
terminated or, if later, at any payment date previously elected by the
participant. If no earlier payment date applies, the Obligations attributable to
the participant's Compensation Deferrals and Matching Contributions will be
payable when amounts attributable to the Discretionary Contributions made by the
Registrant for the participant become payable.

                                      -3-
If the amount available for distribution on any given payment date is
less than $50,000, then the entire amount shall be distributed to the
participant in one lump sum payment, regardless of the participant's election.
If the amount distributable on any given payment date equals or exceeds $50,000,
then the amount will be paid either in one lump sum payment or, if elected by
the participant as a part of his or her deferral election, in twenty or forty
quarterly payments. Under certain circumstances, a participant may elect to
further defer payments otherwise payable on a specified distribution date, but
that election must be made more than 12 months before the specified distribution
date and a participant may make an election to further defer those payments only
once.

         If the participant dies while employed by the registrant, all of his or
her Deferred Compensation Payment Obligations shall be paid to the participant's
beneficiary in a lump sum. If the participant dies after termination of his or
her employment with the Registrant, all of the participant's undistributed
vested Deferred Compensation Payment Obligations shall be paid to the
participant's beneficiary in one lump sum payment, except that amounts that were
being distributed to the participant in installment payments shall continue to
be paid in those installments unless the Registrant elects to accelerate those
payments.

         No amounts payable to participants or beneficiaries under the Plan
will, except as otherwise specifically provided by law, be subject in any matter
to anticipation, alienation, attachment, garnishment, sale, transfer, assignment
(either at law or in equity), levy, execution, pledge, encumbrance, charge or
any other legal or equitable process, and any attempt to do so will be void.
Notwithstanding the foregoing, however, participants may designate any person or
persons to receive such benefits as may be payable under the Plan upon or after
the participant's death. If no such beneficiary designation is made, or if no
beneficiary is living at the time of a participant's death, benefits will be
paid to the participant's spouse, if then living, but otherwise to the
participant's living descendants, if any, but, if none, to the participant's
estate.

         Deferred Compensation Payment Obligations are not subject to redemption
by the Registrant, in whole or in part, prior to the distribution dates selected
by the respective participants under the Plan. Notwithstanding the foregoing,
however, the Registrant has reserved the right to amend or terminate the Plan at
any time, provided that no amendment of the Plan shall deprive a participant or
a beneficiary of a right accrued under the Plan prior to the date of the
amendment.

ITEM 5.   INTERESTS OF NAMED EXPERTS AND COUNSEL.

         Not Applicable

ITEM 6.   INDEMNIFICATION OF DIRECTORS AND OFFICERS.

         The Registrant is a Delaware corporation. Section 145 of the Delaware
General Corporation Law (the "DGCL") provides that a Delaware corporation has
the power to indemnify its officers and directors in certain circumstances.

                                      -4-
Subsection (a) of Section 145 of the DGCL empowers a corporation to
indemnify any director or officer, or former director or officer, who was or is
a party or is threatened to be made a party to any threatened, pending or
completed action, suit or proceeding, whether civil, criminal, administrative or
investigative (other than an action by or in the right of the corporation) by
reason of his or her service as director, officer, employee or agent of the
corporation, or his or her service, at the corporation's request, as a director,
officer, employee or agent of another corporation or enterprise, against
expenses (including attorneys' fees), judgments, fines and amounts paid in
settlement actually and reasonably incurred in connection with such action, suit
or proceeding provided that such director or officer acted in good faith and in
a manner reasonably believed to be in or not opposed to the best interests of
the corporation, and, with respect to any criminal action or proceeding,
provided that such director or officer had no reasonable cause to believe his or
her conduct was unlawful.

         Subsection (b) of Section 145 empowers a corporation to indemnify any
director or officer, or former director or officer, who was or is a party or is
threatened to be made a party to any threatened, pending or completed action or
suit by or in the right of the corporation to procure a judgment in its favor by
reason of the fact that such person acted in any of the capacities set forth
above, against expenses (including attorneys' fees) actually and reasonably
incurred in connection with the defense or settlement of such action or suit
provided that such director or officer acted in good faith and in a manner he or
she reasonably believed to be in or not opposed to the best interests of the
corporation, except that no indemnification may be made in respect of any claim,
issue or matter as to which such director or officer shall have been adjudged to
be liable to the corporation unless and only to the extent that the Court of
Chancery or the court in which such action or suit was brought shall determine
upon application that, despite the adjudication of liability but in view of all
the circumstances of the case, such director or officer is fairly and reasonably
entitled to indemnity for such expenses which the court shall deem proper.

         Section 145 further provides that, to the extent a director or officer
of a corporation has been successful in the defense of any action, suit or
proceeding referred to in subsections (a) or (b) or in the defense of any claim,
issue or matter therein, he or she shall be indemnified against expenses
(including attorneys' fees) actually and reasonably incurred by him in
connection therewith; provided that indemnification provided for by Section 145
or granted pursuant thereto shall not be deemed exclusive of any other rights to
which the indemnified party may be entitled; and empowers the corporation to
purchase and maintain insurance on behalf of a director or officer of the
corporation against any liability asserted against him or her or incurred by him
or her in any such capacity or arising out of his or her status as such whether
or not the corporation would have the power to indemnify him or her against such
liabilities under Section 145.

         Article VII of the Bylaws of the Registrant provides in substance that
the Registrant shall indemnify directors and officers against all liability and
related expenses incurred in connection with the affairs of the Registrant if:
(a), in the case of actions not by or in the right of the Registrant, the
director or officer acted in good faith and in a manner he or she reasonably
believed to be in or not opposed to the best interests of the Registrant, and
(with respect to a criminal proceeding) had no reasonable cause to believe his
or her conduct was unlawful; and (b), in the case of actions by or in the right
of the Registrant, the director or officer acted in good

                                      -5-
faith and in a manner he or she reasonably believed to be in or not opposed to
the best interests of the Registrant, provided that no indemnification shall be
made for a claim as to which the director or officer is adjudged liable for
negligence or misconduct unless (and only to the extent that) an appropriate
court determines that, in view of all the circumstances, such person is fairly
and reasonably entitled to indemnity.

         In addition, Section 102(b)(7) of the DGCL permits Delaware
corporations to include a provision in their certificates of incorporation
eliminating or limiting the personal liability of a director to the corporation
or its stockholders for monetary damages for breach of fiduciary duty as a
director, provided that such provisions shall not eliminate or limit the
liability of a director (i) for any breach of the director's duty of loyalty to
the corporation or its stockholders, (ii) for acts or omissions not in good
faith or that involve intentional misconduct or a knowing violation of law,
(iii) for unlawful payment of dividends or other unlawful distributions, or (iv)
for any transactions from which the director derived an improper personal
benefit. Article Twelve of the Registrant's Restated Certificate of
Incorporation contains such a provision.

         The Registrant maintains Directors' and Officers' liability insurance
with various insurance providers.

ITEM 7.   EXEMPTION FROM REGISTRATION CLAIMED.

         Not Applicable

ITEM 8.   EXHIBITS.

        Exhibit No.  Description of Exhibit
        -----------  ----------------------

            5        Opinion of Miles & Stockbridge P.C.

            23       Consent of Experts (the consent of counsel is included in
                     Exhibit 5).

ITEM 9.   UNDERTAKINGS.

         (a) The undersigned registrant hereby undertakes:

                  (1) To file, during any period in which offers or sales are
being made, a post-effective amendment to this registration statement:

                           (i) To include any prospectus required by Section
10(a)(3) of the Securities Act of 1933;

                           (ii) To reflect in the prospectus any facts or events
arising after the effective date of the registration statement (or the most
recent post-effective amendment thereof) which, individually or in the
aggregate, represent a fundamental change in the information set forth in the
registration statement; and

                                      -6-
(iii) To include any material information with
respect to the plan of distribution not previously disclosed in the registration
statement or any material change to such information in the registration
statement;

                  Provided, however, that subparagraphs (1)(i) and (1)(ii) do
not apply if the information required to be included in a post-effective
amendment by those paragraphs is contained in periodic reports filed by the
registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange
Act of 1934 that are incorporated by reference in the registration statement.

                  (2) That, for the purpose of determining any liability under
the Securities Act of 1933, each such post-effective amendment shall be deemed
to be a new registration statement relating to the securities offered therein,
and the offering of such securities at that time shall be deemed to be the
initial bona fide offering thereof.

                  (3) To remove from registration by means of a post-effective
amendment any of the securities being registered which remain unsold at the
termination of the offering.

         (b) The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Securities Exchange Act of 1934 (and, where applicable, each filing of an
employee benefit plan's annual report pursuant to Section 15(d) of the
Securities Exchange Act of 1934) that is incorporated by reference in the
registration statement shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

         (c) Insofar as indemnification for liabilities arising under the
Securities Act of 1933 may be permitted to directors, officers and controlling
persons of the registrant pursuant to the foregoing provisions, or otherwise,
the registrant has been advised that in the opinion of the Securities and
Exchange Commission such indemnification is against public policy as expressed
in the Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
registrant of expenses incurred or paid by a director, officer or controlling
person of the registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Act and will
be governed by the final adjudication of such issue.

                                      -7-
SIGNATURES

         Pursuant to the requirements of the Securities Act, the registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Columbia, State of Maryland, on December 30, 1999.

                                           Magellan Health Services, Inc.

                                           By: /s/ Mark S. Demilio
                                               -------------------------------
                                                Mark S. Demilio
                                                Executive Vice President and
                                                General Counsel

         KNOW ALL MEN BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Clifford W. Donnelly and Mark S. Demilio
and each of them, his or her true and lawful attorneys-in-fact and agents, with
full power of substitution and resubstitution, for him or her and in his or her
name, place and stead, in any and all capacities, to sign any and all amendments
to this registration statement, and to file the same, with all exhibits thereto,
and other documents in connection therewith, with the Securities and Exchange
Commission, granting unto said attorneys-in-fact and agents full power and
authority to do and perform each and every act and thing requisite and necessary
to be done in and about the premises, as fully to all intents and purposes as he
or she might or could do in person, hereby ratifying and confirming all that
said attorneys-in-fact and agents, or their substitute or substitutes, may
lawfully do or cause to be done by virtue hereof.

         Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed by the following persons in the
capacities and on the dates indicated.

Signature                     Title                             Date
---------                     -----                             ----

/s/ HENRY T. HARBIN           President, Chief Executive      December 30, 1999
--------------------------    Officer and Director
Henry T. Harbin, M.D.

/s/ CLIFFORD W. DONNELLY      Executive Vice President        December 30, 1999
--------------------------    and Chief Financial Officer
Clifford W. Donnelly

/s/ THOMAS C. HOFMEISTER      Senior Vice President and       December 30, 1999
--------------------------    Chief Accounting Officer
Thomas C. Hofmeister

                              Director                        December __, 1999
--------------------------
David Bonderman

/s/ JONATHAN J. COSLET        Director                        December 30, 1999
--------------------------
Jonathan J. Coslet

                                      -8-
Signature                     Title                           Date
---------                     -----                           ----

/s/ G. FRED DIBONA, JR.       Director                        December 30, 1999
--------------------------
G. Fred DiBona, Jr.

                              Director                        December __, 1999
--------------------------
Andre C. Dimitriadis

/s/ A.D. FRAZIER, JR.         Director                        December 30, 1999
--------------------------
A. D. Frazier, Jr.

/s/ GERALD L. MCMANIS         Director                        December 30, 1999
--------------------------
Gerald L. McManis

                              Director                        December __, 1999
--------------------------
Daniel S. Messina

/s/ ROBERT W. MILLER          Director                        December 30, 1999
--------------------------
Robert W. Miller

                              Director                        December __, 1999
--------------------------
Darla D. Moore

/s/ JEFFREY A. SONNENFELD     Director                        December 30, 1999
--------------------------
Jeffrey A. Sonnenfeld

/s/ JAMES B. WILLIAMS         Director                        December 30, 1999
--------------------------
James B. Williams

                                      -9-