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  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="5" face="Times New Roman" style="font-size:18.0pt;font-weight:bold;">UNITED STATES</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="5" face="Times New Roman" style="font-size:18.0pt;font-weight:bold;">SECURITIES AND EXCHANGE
  COMMISSION</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">WASHINGTON, D.C. 20549</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <div align="center" style="margin:0in 0in .0001pt;text-align:center;"><hr size="1" width="25%" noshade color="black" align="center"></div>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="5" face="Times New Roman" style="font-size:18.0pt;font-weight:bold;">FORM&nbsp;8-K</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="3" face="Times New Roman" style="font-size:12.0pt;font-weight:bold;">CURRENT
  REPORT</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="3" face="Times New Roman" style="font-size:12.0pt;font-weight:bold;">Pursuant
  to Section&nbsp;13 or 15(d)&nbsp;of the</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="3" face="Times New Roman" style="font-size:12.0pt;font-weight:bold;">Securities
  Exchange Act of 1934</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Date of Report (Date of earliest event reported):&#160; <b>May&nbsp;1, 2008</b></font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="5" face="Times New Roman" style="font-size:18.0pt;font-weight:bold;">United Therapeutics Corporation</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;letter-spacing:-.15pt;">(Exact Name of Registrant as Specified in
  Charter)</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
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    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;letter-spacing:-.15pt;">Delaware</font></b></p>
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    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:1.0pt;font-weight:bold;letter-spacing:-.15pt;">&nbsp;</font></b></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;letter-spacing:-.15pt;">000-26301</font></b></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:1.0pt;font-weight:bold;letter-spacing:-.15pt;">&nbsp;</font></b></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;letter-spacing:-.15pt;">52-1984749</font></b></p>
    </td>
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    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;letter-spacing:-.15pt;">(State or Other</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;letter-spacing:-.15pt;">&nbsp;</font></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;letter-spacing:-.15pt;">(Commission</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;letter-spacing:-.15pt;">&nbsp;</font></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;letter-spacing:-.15pt;">(I.R.S. Employer</font></p>
    </td>
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    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;letter-spacing:-.15pt;">Jurisdiction of</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;letter-spacing:-.15pt;">&nbsp;</font></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;letter-spacing:-.15pt;">File Number)</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;letter-spacing:-.15pt;">&nbsp;</font></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;letter-spacing:-.15pt;">Identification Number)</font></p>
    </td>
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    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;letter-spacing:-.15pt;">Incorporation)</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;letter-spacing:-.15pt;">&nbsp;</font></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:1.0pt;letter-spacing:-.15pt;">&nbsp;</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;letter-spacing:-.15pt;">&nbsp;</font></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:1.0pt;letter-spacing:-.15pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;letter-spacing:-.15pt;">&nbsp;</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;letter-spacing:-.15pt;">&nbsp;</font></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;letter-spacing:-.15pt;">&nbsp;</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;letter-spacing:-.15pt;">&nbsp;</font></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;letter-spacing:-.15pt;">&nbsp;</font></p>
    </td>
   </tr>
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    <td width="66%" colspan="3" valign="top" style="padding:0in 0in 0in 0in;width:66.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">1110 Spring Street</font></b></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:1.0pt;font-weight:bold;letter-spacing:-.15pt;">&nbsp;</font></b></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:1.0pt;font-weight:bold;letter-spacing:-.15pt;">&nbsp;</font></b></p>
    </td>
   </tr>
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    <td width="66%" colspan="3" valign="top" style="padding:0in 0in 0in 0in;width:66.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;letter-spacing:-.15pt;">Silver Spring, MD</font></b></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;letter-spacing:-.15pt;">&nbsp;</font></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;letter-spacing:-.15pt;">20910</font></b></p>
    </td>
   </tr>
   <tr>
    <td width="66%" colspan="3" valign="top" style="padding:0in 0in 0in 0in;width:66.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;letter-spacing:-.15pt;">(Address of Principal
    Executive Offices)</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.0%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;letter-spacing:-.15pt;">&nbsp;</font></p>
    </td>
    <td width="32%" valign="top" style="padding:0in 0in 0in 0in;width:32.0%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;letter-spacing:-.15pt;">(Zip Code)</font></p>
    </td>
   </tr>
  </table>
  
  </div>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;letter-spacing:-.15pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Registrant&#146;s telephone number, including area code:</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">(301) 608-9292</font></b></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <div align="center" style="margin:0in 0in .0001pt;text-align:center;"><hr size="1" width="25%" noshade color="black" align="center"></div>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Check the appropriate box below if the Form&nbsp;8-K
  filing is intended to simultaneously satisfy the filing obligation of the
  registrant under any of the following provisions:</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="margin:0in 0in .0001pt .25in;text-align:left;text-indent:-.25in;"><font size="2" face="Wingdings" style="font-size:10.0pt;">o</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font><font size="2" style="font-size:10.0pt;">Written communications pursuant to Rule&nbsp;425
  under the Securities Act (17 CFR 230.425)</font></p>
  
  <p align="left" style="margin:0in 0in .0001pt .25in;text-align:left;text-indent:-.25in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="margin:0in 0in .0001pt .25in;text-align:left;text-indent:-.25in;"><font size="2" face="Wingdings" style="font-size:10.0pt;">o</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font><font size="2" style="font-size:10.0pt;">Soliciting material pursuant to Rule&nbsp;14a-12
  under the Exchange Act (17 CFR 240.14a-12)</font></p>
  
  <p align="left" style="margin:0in 0in .0001pt .25in;text-align:left;text-indent:-.25in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="margin:0in 0in .0001pt .25in;text-align:left;text-indent:-.25in;"><font size="2" face="Wingdings" style="font-size:10.0pt;">o</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font><font size="2" style="font-size:10.0pt;">Pre-commencement communications pursuant
  to Rule&nbsp;14d-2(b)&nbsp;under the Exchange Act (17 CFR 240.14d-2(b))</font></p>
  
  <p align="left" style="margin:0in 0in .0001pt .25in;text-align:left;text-indent:-.25in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="left" style="margin:0in 0in .0001pt .25in;text-align:left;text-indent:-.25in;"><font size="2" face="Wingdings" style="font-size:10.0pt;">o</font><font size="1" style="font-size:3.0pt;">&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; </font><font size="2" style="font-size:10.0pt;">Pre-commencement communications pursuant
  to Rule&nbsp;13e-4(c)&nbsp;under the Exchange Act (17 CFR 240.13e-4(c))</font></p>
  
  <div style="border:none;border-bottom:double windowtext 6.0pt;padding:0in 0in 0in 0in;">
  
  <p align="left" style="border:none;margin:0in 0in .0001pt .25in;padding:0in;text-align:left;text-indent:-.25in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  </div>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <div style="margin:0in 0in .0001pt;"><hr size="3" width="100%" noshade color="#010101" align="left"></div>
  
  </div>
  <!-- SEQ.=1,FOLIO='',FILE='C:\JMS\C900124\08-12951-1\task2904911\12951-1-ba.htm',USER='c900124',CD='Apr 30 11:37 2008' -->
  
  
  <br clear="all" style="page-break-before:always;">
  
  
  <div>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Item
  2.02.&#160; Results of Operations and
  Financial Condition.</font></b></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">On May&nbsp;1, 2008,
  United Therapeutics Corporation (the &#147;Company&#148;) issued a press release setting
  forth its earnings for the Company&#146;s quarterly period ended March&nbsp;31,
  2008.</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">A copy of the press
  release is attached hereto as Exhibit&nbsp;99.1.</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Item
  9.01.&#160; Exhibits</font></b></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">This information shall
  not be deemed to be &#147;filed&#148; for the purposes of Section&nbsp;18 of the
  Securities Exchange Act of 1934, as amended, or otherwise subject to liability
  under that section, nor shall it be deemed incorporated by reference into any filing
  under the Securities Act of 1934, as amended, except as shall be expressly set
  forth by specific reference in such filing.</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">(d)&nbsp; Exhibits</font></p>
  
  <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <table border="0" cellspacing="0" cellpadding="0" width="93%" style="border-collapse:collapse;margin-left:.5in;width:93.34%;">
   <tr>
    <td width="9%" valign="bottom" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in 0in 0in 0in;width:9.64%;">
    <p style="margin:0in 0in .0001pt;"><b><font size="1" face="Times New Roman" style="font-size:8.0pt;font-weight:bold;">Exhibit&nbsp;No.</font></b></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.14%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="1" face="Times New Roman" style="font-size:1.0pt;font-weight:bold;">&nbsp;</font></b></p>
    </td>
    <td width="88%" valign="bottom" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in 0in 0in 0in;width:88.22%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="1" face="Times New Roman" style="font-size:8.0pt;font-weight:bold;">Description&nbsp;of&nbsp;Exhibit</font></b></p>
    </td>
   </tr>
   <tr>
    <td width="9%" valign="top" style="border:none;padding:0in 0in 0in 0in;width:9.64%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.14%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="88%" valign="top" style="border:none;padding:0in 0in 0in 0in;width:88.22%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="9%" valign="top" style="padding:0in 0in 0in 0in;width:9.64%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">99.1</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.14%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="88%" valign="top" style="padding:0in 0in 0in 0in;width:88.22%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Press release dated
    May&nbsp;1, 2008</font></p>
    </td>
   </tr>
  </table>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">2</font></p>
  
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  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">SIGNATURE</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">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.</font></p>
  
  <p style="margin:0in 0in .0001pt;text-indent:.5in;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <table border="0" cellspacing="0" cellpadding="0" width="100%" style="border-collapse:collapse;width:100.0%;">
   <tr>
    <td width="45%" valign="top" style="padding:0in 0in 0in 0in;width:45.16%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="54%" colspan="3" valign="top" style="padding:0in 0in 0in 0in;width:54.84%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">UNITED
    THERAPEUTICS CORPORATION</font></p>
    </td>
   </tr>
   <tr>
    <td width="45%" valign="top" style="padding:0in 0in 0in 0in;width:45.16%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="3%" valign="top" style="padding:0in 0in 0in 0in;width:3.34%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="51%" colspan="2" valign="top" style="padding:0in 0in 0in 0in;width:51.5%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="45%" valign="top" style="padding:0in 0in 0in 0in;width:45.16%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="3%" valign="top" style="padding:0in 0in 0in 0in;width:3.34%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="51%" colspan="2" valign="top" style="padding:0in 0in 0in 0in;width:51.5%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="45%" valign="top" style="padding:0in 0in 0in 0in;width:45.16%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Dated: May&nbsp;1, 2008</font></p>
    </td>
    <td width="3%" valign="top" style="padding:0in 0in 0in 0in;width:3.34%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">By:</font></p>
    </td>
    <td width="51%" colspan="2" valign="top" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in 0in 0in 0in;width:51.5%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;&nbsp;&nbsp;&nbsp;/s/
    Paul A. Mahon</font></p>
    </td>
   </tr>
   <tr>
    <td width="45%" valign="top" style="padding:0in 0in 0in 0in;width:45.16%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="3%" valign="top" style="padding:0in 0in 0in 0in;width:3.34%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="7%" valign="top" style="border:none;padding:0in 0in 0in 0in;width:7.34%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;&nbsp;&nbsp;&nbsp;Name:</font></p>
    </td>
    <td width="44%" valign="top" style="border:none;border-top:solid windowtext 1.0pt;padding:0in 0in 0in 0in;width:44.16%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Paul A. Mahon</font></p>
    </td>
   </tr>
   <tr>
    <td width="45%" valign="top" style="padding:0in 0in 0in 0in;width:45.16%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="3%" valign="top" style="padding:0in 0in 0in 0in;width:3.34%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="7%" valign="top" style="padding:0in 0in 0in 0in;width:7.34%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;&nbsp;&nbsp;&nbsp;Title:</font></p>
    </td>
    <td width="44%" valign="top" style="padding:0in 0in 0in 0in;width:44.16%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">General Counsel</font></p>
    </td>
   </tr>
  </table>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">3</font></p>
  
  <div style="margin:0in 0in .0001pt;"><hr size="3" width="100%" noshade color="#010101" align="left"></div>
  
  </div>
  <!-- SEQ.=1,FOLIO='3',FILE='C:\JMS\C900124\08-12951-1\task2904911\12951-1-ba.htm',USER='c900124',CD='Apr 30 11:37 2008' -->
  
  
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  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><b><font size="2" face="Times New Roman" style="font-size:10.0pt;font-weight:bold;">Exhibit&nbsp;Index</font></b></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;text-autospace:none;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <table border="0" cellspacing="0" cellpadding="0" width="100%" style="border-collapse:collapse;width:100.0%;">
   <tr>
    <td width="8%" valign="bottom" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in 0in 0in 0in;width:8.92%;">
    <p style="margin:0in 0in .0001pt;"><b><font size="1" face="Times New Roman" style="font-size:8.0pt;font-weight:bold;">Exhibit&nbsp;No.</font></b></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.32%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="1" face="Times New Roman" style="font-size:1.0pt;font-weight:bold;">&nbsp;</font></b></p>
    </td>
    <td width="88%" valign="bottom" style="border:none;border-bottom:solid windowtext 1.0pt;padding:0in 0in 0in 0in;width:88.76%;">
    <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><b><font size="1" face="Times New Roman" style="font-size:8.0pt;font-weight:bold;">Description&nbsp;of&nbsp;Exhibit</font></b></p>
    </td>
   </tr>
   <tr>
    <td width="8%" valign="top" style="border:none;padding:0in 0in 0in 0in;width:8.92%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.32%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
    <td width="88%" valign="top" style="border:none;padding:0in 0in 0in 0in;width:88.76%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
    </td>
   </tr>
   <tr>
    <td width="8%" valign="top" style="padding:0in 0in 0in 0in;width:8.92%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">99.1</font></p>
    </td>
    <td width="2%" valign="bottom" style="padding:0in 0in 0in 0in;width:2.32%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:1.0pt;">&nbsp;</font></p>
    </td>
    <td width="88%" valign="top" style="padding:0in 0in 0in 0in;width:88.76%;">
    <p style="margin:0in 0in .0001pt;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">Press release dated
    May&nbsp;1, 2008</font></p>
    </td>
   </tr>
  </table>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">&nbsp;</font></p>
  
  <p align="center" style="margin:0in 0in .0001pt;text-align:center;"><font size="2" face="Times New Roman" style="font-size:10.0pt;">4</font></p>
  
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metadata_filer: {"company-data": {"conformed-name": "UNITED THERAPEUTICS CORP", "cik": "0001082554", "assigned-sic": "2834", "irs-number": "521984749", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "000-26301", "film-number": "08791914"}, "business-address": {"street1": "1110 SPRING ST", "city": "SILVER SPRING", "state": "MD", "zip": "20910", "phone": "3016089292"}, "mail-address": {"street1": "1110 SPRING ST", "city": "SILVER SPRING", "state": "MD", "zip": "20910"}}
text: 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
  Date of Report (Date of earliest event reported):
  May 1, 2008
  United Therapeutics Corporation
  (Exact Name of Registrant as Specified in
  Charter)
  Delaware
  000-26301
  52-1984749
  (State or Other
  (Commission
  (I.R.S. Employer
  Jurisdiction of
  File Number)
  Identification Number)
  Incorporation)
  1110 Spring Street
  Silver Spring, MD
  20910
  (Address of Principal
    Executive Offices)
  (Zip Code)
  Registrant's telephone number, including area code:
  (301) 608-9292
  Check the appropriate box below if the Form 8-K
  filing is intended to simultaneously satisfy the filing obligation of the
  registrant under any of the following provisions:
  o
  Written communications pursuant to Rule 425
  under the Securities Act (17 CFR 230.425)
  o
  Soliciting material pursuant to Rule 14a-12
  under the Exchange Act (17 CFR 240.14a-12)
  o
  Pre-commencement communications pursuant
  to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
  o
  Pre-commencement communications pursuant
  to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))
  Item
  2.02.  Results of Operations and
  Financial Condition.
  On May 1, 2008,
  United Therapeutics Corporation (the "Company") issued a press release setting
  forth its earnings for the Company's quarterly period ended March 31,
  2008.
  A copy of the press
  release is attached hereto as Exhibit 99.1.
  Item
  9.01.  Exhibits
  This information shall
  not be deemed to be "filed" for the purposes of Section 18 of the
  Securities Exchange Act of 1934, as amended, or otherwise subject to liability
  under that section, nor shall it be deemed incorporated by reference into any filing
  under the Securities Act of 1934, as amended, except as shall be expressly set
  forth by specific reference in such filing.
  (d)  Exhibits
  Exhibit No.
  Description of Exhibit
  99.1
  Press release dated
    May 1, 2008
  2
  SIGNATURE
  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.
  UNITED
    THERAPEUTICS CORPORATION
  Dated: May 1, 2008
  By:
  /s/
    Paul A. Mahon
  Name:
  Paul A. Mahon
  Title:
  General Counsel
  3
  Exhibit Index
  Exhibit No.
  Description of Exhibit
  99.1
  Press release dated
    May 1, 2008
  4