Exhibit 10.1

EMPLOYMENT AGREEMENT

THIS EMPLOYMENT AGREEMENT (this “Agreement”) is entered into as of February 16, 2011 by and between United Therapeutics Corporation (the “Company”) and Michael Benkowitz (the “Executive”).

WHEREAS, the Company desires to employ Executive as Executive Vice President for Organizational Development, subject to the terms and conditions herein set forth;

NOW, THEREFORE, in consideration of the promises and mutual covenants contained herein, and for other good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, the parties hereto agree as follows.

1.                                       Employment .  Upon the other terms and conditions hereinafter stated, the Company agrees to employ the Executive and the Executive agrees to accept employment by the Company for the term set forth in Section 2 hereof and in the position and with the duties and responsibilities set forth in Section 3 hereof.  Executive warrants that he is under no restriction that would prevent him from entering into this Agreement and from complying with all of its provisions to their fullest extent.

2.                                       Term .  The term of the Executive’s employment under this Agreement will commence no later than April 15, 2011, and end on December 31, 2013 (the “Initial Term”), and thereafter shall continue from year to year for additional one-year terms (the “Additional Terms”), unless and until either party shall give notice of such party’s intent to terminate not less than 60 days prior to the end of the then-current Initial Term or Additional Term, which termination shall be effective at the expiration of said term, or until sooner terminated as hereinafter set forth.

3.                                       Position and Duties .

(a)                                  Executive shall serve as Executive Vice President for Organizational Development, with such duties and responsibilities (i) as are normally performed by such an executive of a biotechnology company including, without limitation, ensuring that the Company’s infrastructure develops in an optimal manner consistent with the Company’s culture and responsibility for the Company’s Human Resources function, and (ii) as may be assigned to Executive from time to time by the Company’s CEO.  The Executive shall report to the Company’s CEO.  The Executive shall at all times exert his best efforts and loyalty on behalf of the Company and shall devote full time and attention to such employment.

(b)                                  Executive shall perform his duties from an office leased by the Company in Marin County, California, although Executive will travel as necessary or desirable to fulfill his duties and responsibilities to the Company, including at a minimum a monthly visit to a Company office as needed. Executive shall have access to an administrative assistant, whether located in the Marin County office or in another Company office, as reasonably determined by the parties.  If Executive desires to relocate his residence in order to work from another Company office, then upon approval of the Company’s CEO,

Company shall reimburse Executive up to a maximum of $125,000 for all relocation expenses directly and reasonably incurred by him as a result of his relocation in accordance with the Company’s relocation reimbursement policy then in effect.

(c)                                   The Executive agrees to abide by all employment guidelines and policies as may be developed from time to time by the Company and applicable to all employees of the Company, including, without limitation, the United Therapeutics Corporation Company Manual, the United Therapeutics Corporation Securities Trades by Company Personnel Policy and the United Therapeutics Corporation Media & Analyst Communication Policy.

4.                                       Compensation and Related Matters .  The Company shall provide the following compensation and benefits to the Executive:

(a)                                  The Company shall pay to the Executive an annual base salary of $300,000 (the “Base Salary”) such annual base salary to be subject to review and increase annually by the Company at the Company’s discretion.  The Base Salary shall be payable semi-monthly or in such other installments as shall be consistent with the Company’s payroll procedures.  The Company shall deduct and withhold all necessary social security and withholding taxes and any other similar sums required by law or authorized by the Executive with respect to payment of the Base Salary and all other amounts and benefits payable under this Agreement.

(b)                                  Executive shall be entitled to receive an annual cash bonus target opportunity equivalent to 35% of Base Salary and an annual share tracking award plan (STAP) award bonus target opportunity of 40,000 STAP awards, both of the foregoing to be awarded in accordance with the Company’s cash and STAP bonus policies in effect from time to time.

(c)                                   Executive is eligible to participate in the standard health, dental, vision care, short and long-term disability, life insurance and 401(k) benefits provided to the Company’s employees.  Detailed benefits information including employee costs will be included in Executive’s new hire package.  Additionally, in Executive’s new hire package Executive will receive a copy of the Employee Handbook that explains many of United Therapeutics’ policies and procedures.

(d)                                  Executive will receive a one-time lump sum sign-on bonus of $75,000 paid with Executive’s first paycheck after the date Executive’s employment commences.  This lump sum payment will also be subject to normal deductions and withholdings.  If Executive voluntarily terminates his employment within one year from the date this bonus is paid, Executive will be required to reimburse the Company for the entire amount of this bonus immediately on demand.  Executive hereby authorizes the Company to make a deduction from Executive’s salary, or any other sums due to Executive, to recover this payment.

(e)                                   Executive will be awarded 40,000 STAP awards with an exercise price equal to the closing price of the Company’s common stock on the NASDAQ Global

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Select Market on the date Executive’s employment commences, vesting in one-quarter increments on the first, second, third, and fourth anniversaries of the grant date, which is the date employment commences.   These awards are valid for ten years from the date of grant, and vest only for so long as Executive remains employed by the Company. All unvested awards expire upon termination of Executive’s employment, except as provided in Section 8(e) below.

(f)                                    Executive will be awarded 50,000 Change of Control STAP awards with an exercise price equal to the closing price of the Company’s common stock on the NASDAQ Global Select Market on the date Executive’s employment commences, vesting 100% upon the occurrence of a Change of Control of the Company (as defined in Section 8(e)(3)(B) below) on or before December 31, 2013.  These awards shall expire on December 31, 2013, and vest only if Executive remains employed by the Company on the date of any Change of Control.  All unvested awards expire upon termination of Executive’s employment.  Additional terms and conditions applicable to this award shall be defined under the share tracking award plan under which such award is granted, and the form of Terms and Conditions attached hereto as Exhibit A .

5.                                       Expenses .  The Executive shall be reimbursed by the Company for reasonable travel and other expenses that are incurred and accounted for in accordance with the Company’s normal practices.

6.                                       Vacation .  For Executive’s first year of employment he will be entitled to 15 days vacation, earned on a pro-rated basis depending on Executive’s date of hire. Additional vacation time will be accrued after each completed year of service based on the Executive’s hire date in accordance with the Employee Handbook.

7.                                       Termination of Employment .

(a)                                  The Executive’s employment hereunder shall terminate upon the Executive’s death.

(b)                                  The Company may terminate the Executive’s employment hereunder as set forth in Section 2 above, and under the following circumstances:

(i)                                      If, as a result of the Executive’s incapacity or other disability owing to physical or mental illness, the Executive shall have been unable to perform all of the Executive’s material duties hereunder by reason of illness, or physical or mental disability or other similar capacity, which inability shall continue for more than two (2) consecutive months, the Company may terminate the Executive’s employment hereunder.

(ii)                                   The Company may terminate the Executive’s employment hereunder for “Cause.”  For purposes of this Agreement, the Company shall have “Cause” to terminate the Executive’s employment hereunder upon the (A) failure of the Executive (other than for reasons described in Sections 7(a) and 7(b)(i) hereof) to perform or observe any of the material terms or provisions of this Agreement;  (B) negligent or unsatisfactory performance of the Executive’s duties under this Agreement and the failure of the Executive,

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within 10 days after receipt of notice from the Company setting forth in reasonable detail the nature of the Executive’s negligent or unsatisfactory performance, (i) to provide the Company with a reasonably satisfactory explanation of the Executive’s actions (or inaction) and (ii) to correct to the satisfaction of the Company any reasonably identified deficiencies; (C) employment- or profession-related misconduct or other employment- or profession-related similar action on the part of the Executive; (D) conviction of the Executive of a crime involving a felony, fraud, embezzlement or the like; or (E) misappropriation of the Company funds or misuse of the Company’s assets by Executive, or other act of dishonesty by Executive.

(c)                                   Any termination of the Executive’s employment by the Company or by the Executive (other than pursuant to Section 7(a) hereof) shall be communicated by written “Notice of Termination” to the other party hereto in accordance with Section 11(c) hereof, which shall indicate the specific termination provision in this Agreement relied upon, if any, and shall set forth in reasonable detail the facts and circumstances claimed to provide a basis for termination of the Executive’s employment under the provision so indicated.

(d)                                  For purposes of this Agreement, the “Date of Termination” shall mean (i) if the Executive’s employment is terminated by the Executive’s death, the date of the Executive’s death;  (ii) if the Executive’s employment is terminated pursuant to Section 7(b)(i) hereof, thirty (30) days after the Notice of Termination; provided , however , that the Executive shall not have returned to the performance of the Executive’s duties on a full-time basis during such thirty (30) day period; (iii) if the Executive’s employment is terminated pursuant to Section 7(b)(ii) hereof, the date specified in the Notice of Termination (which date, in the case of termination of Executive’s employment solely pursuant to clause (B) of Section 7(b)(ii) by reason of inadequate performance, shall not be sooner than thirty (30) days from the date of the Notice of Termination); and (iv) if the Executive’s employment is terminated for any other reason, the date on which the Notice of Termination is given.

(e)                                   Following termination of this Agreement, Executive shall promptly make himself reasonably available to assist the Company with any information or other requests.

8.                                       Compensation Upon Termination .

(a)                                  If the Executive’s employment is terminated by the Executive’s death, the Company shall pay to the Executive’s estate or as may be directed by the legal representatives of such estate, the Executive’s full Base Salary through the Date of Termination at the rate in effect at the time of the Executive’s death.

(b)                                  During any period that the Executive fails to perform the Executive’s duties hereunder solely as a result of incapacity due to physical or mental illness (“disability period”), the Executive shall continue to receive the Executive’s full base salary through the Date of Termination at the rate in effect at the time the Notice of Termination is given and all other unpaid amounts, if any, to which the Executive is entitled as of the Date of Termination in connection with any fringe benefits or under any incentive compensation plan or program of the Company hereof, at the time such payments are due; provided that payments so made

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to the Executive during the disability period shall be reduced by the sum of the amounts, if any, payable to the Executive at or prior to the time of any such payment under disability benefit plans of the Company and which amounts were not previously applied to reduce any such payment.

(c)                                   If the Executive shall terminate the Executive’s employment or the Company terminates the Executive’s employment for Cause as provided in Section 7(b)(ii) hereof, the Company shall pay the Executive the Executive’s full Base Salary through the Date of Termination at the rate in effect at the time the Notice of Termination is given, and the Company shall have no further obligations to the Executive under this Agreement.

(d)                                  Subject to Section 8(e) below, if the Company terminates Executive’s employment without Cause, the Company shall pay to Executive an amount equal to Executive’s Base Salary for the time remaining in the then-current Initial Term or Additional Term, payable in semi-monthly installments and as is otherwise consistent with the Company’s payroll procedures.

(e)                                   If Executive’s termination occurs during the Term of this Agreement and after of a Change of Control, regardless of the reason for the termination and regardless of whether the termination is initiated by Executive or by the Company, the Executive will be entitled to the following:

(i)                                      a lump-sum amount equal to the amount Executive would have been entitled to receive in Base Salary (taking into account any increases that may have occurred after the date hereof) for the time remaining in Executive’s then current Term of employment;

(ii)                                   (A) all unvested STAP awards; (B) all unvested options to purchase shares of the Company’s Common Stock; and (C) all other awards subject to vesting, in each case granted by the Company to Executive prior to Executive’s Date of Termination, shall immediately vest in Executive as of the date of such termination, and the exercise period for each such previously-granted STAP award, option or other award, including those awards previously vested but unexercised, shall be the full remaining duration of the term of each such STAP award, option or other award; and

(iii)                                for purposes of this Agreement (unless otherwise specifically provided), the term “Change of Control” means any transaction that constitutes either (A) a transfer of control of the Company by acquisition, merger, hostile takeover or for any reason whatsoever which qualifies as a “change in the ownership of effective control of the corporation” under Internal Revenue Code section 409A(a)(2)(A)(v); or (B) a “Change of Control” as defined in Section 2.6 of the Company’s Share Tracking Awards Plan, or any successor provision or plan).

(f)                                    Compensation to Executive upon termination described in this Section 8 shall be and is hereby made expressly contingent upon Executive’s ongoing compliance with non-competition, confidentiality, non-solicitation, continuing cooperation and all other obligations of Executive that survive termination of this Agreement.

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9.                                       Intellectual Property Rights .  Because of the highly specialized and technical nature of the business of the Company and the nature and scope of Executive’s employment, Executive agrees that the entire right, title, and interest, in and to all inventions, discoveries, materials, authorship, derivatives and results and proceeds of Executive’s efforts in any form or media, including without limitation, all domestic and foreign patents, trade secrets and copyrights in and to all inventions, processes, written works, and other forms of intellectual property (“Intellectual Property”), which Executive makes, conceives, reduces to practice or develops, in whole or in part, during the term of this Agreement in the furtherance of the Company’s business (whether or not made during the hours of employment or with the use of Company’s materials, facilities or personnel, either solely or jointly with others), or after termination of employment if such Intellectual Property is based upon Confidential Information, shall be solely and exclusively owned by the Company, its successors licensees and assigns, and no other individual or entity shall have any interest therein of any kind or nature.  In full consideration of the compensation provided to Executive by the Company, Executive agrees to each and all of the following:

(a)                      Patents and Trade Secrets .

1.               Executive shall promptly disclose and shall and hereby does assign and transfer to United Therapeutics all right, title and interest in and to any patentable or unpatentable inventions, discoveries, and ideas which are made or conceived in whole or in part by or on behalf of Executive in the course of or as a result of his employment hereunder, or that relate directly to, or involve the use of Confidential Information and the Work.  In the event that Executive has any right in the work which cannot be assigned, Executive agrees to waive enforcement worldwide of such right against United Therapeutics, its successors, distributors, licensees and assigns or, if necessary, hereby grants a fully-paid up worldwide exclusive license to United Therapeutics with the right to sublicense and assign.

2.               Executive shall timely assist United Therapeutics in the filing and prosecution of patent applications covering such inventions, discoveries or ideas and will promptly execute and furnish any and all documents as may be required to establish United Therapeutics’ sole and exclusive ownership thereof.  Executive hereby grants United Therapeutics the exclusive right, and appoints United Therapeutics as Executive’s attorney-in-fact (such power of attorney being coupled with an interest therein) to execute and prosecute an application for domestic and/or foreign patent or other statutory protection, and Executive shall execute and deliver to United Therapeutics, without charge to United Therapeutics but at United Therapeutics’ expense, such other documents of registration and recordation, and do such other acts, such as give testimony in support of Executive’s inventorship, as may be necessary in the opinion of United Therapeutics to vest in United Therapeutics or any other party nominated by United Therapeutics, or otherwise to protect, the exclusive rights conveyed and/or granted to United Therapeutics pursuant to this Agreement.

3.               In the event that United Therapeutics decides not to pursue patent protection for any discovery or creation made by Executive, and instead decides to protect the discovery or creation pursuant to the trade secret laws of any jurisdiction, such decision

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shall not be construed as a waiver of United Therapeutics’ rights pursuant to this Agreement.  At United Therapeutics’ expense, Executive shall also take whatever steps are necessary to sustain United Therapeutics’ claim to such trade secrets, including but not limited to: (i) maintaining the confidential nature of any such discoveries or creations; and (ii) testifying and providing other support and substantiation for United Therapeutics’ claims with regard to the discovery or creation.

4.  With respect to discoveries made by Executive, Executive shall maintain notebooks and other records adequate to describe such discovery to others conversant in the subject of the technology and to establish the date and circumstances of such discovery.  Executive shall notify United Therapeutics of any such discoveries and shall make copies of all documents or reports relating to such discoveries available to United Therapeutics.  Any discovery shall be reported to United Therapeutics regardless of whether, in Executive’s opinion, a given discovery is of value to United Therapeutics, or is protectable under patent, copyright or the laws of any jurisdiction.

(b)       Copyrights .

1.     All materials, authorship, derivatives and other work prepared by Executive in any form or media that relate to the Work (“Authorship”) shall be considered as “Works Made for Hire” (as that term is defined under U.S. Copyright Laws) and, as such shall be owned solely and exclusively by and for the sole and exclusive benefit of United Therapeutics.

2.     In the event that it should be determined that (i) any of such Authorship shall not be considered as a Work Made for Hire for any reason, or (ii) Executive acquires any right, title or interest in or to any Authorship prepared by Executive in any such Authorship, then in either such event, Executive will and hereby does assign and transfer to United Therapeutics all right, title and interest possessed by Executive in all such Authorship and will promptly execute and furnish any and all documents as may be required to establish United Therapeutics’ sole and exclusive ownership thereof.  For the purpose of producing such documentation Executive hereby irrevocably appoints United Therapeutics as its attorney in fact to execute such documents on its behalf, such power of attorney being coupled with an interest therein.  In the event that Executive has any right in the work which cannot be assigned, Executive agrees to waive enforcement worldwide of such right against United Therapeutics, its successors, distributors, licensees and assigns or, if necessary, hereby grants a fully-paid up worldwide exclusive license to United Therapeutics with the right to sublicense and assign.

(c)           Original Work .  Executive agrees that Executive shall not include any material owned by a third party in any written, copyrightable or patentable material furnished or delivered by Executive under this Agreement without the unconditional written consent of the owner of such intellectual property rights unless specific advance written approval is obtained from United Therapeutics for inclusion of such material including third party intellectual property rights.  Executive also agrees that all work (or tangible expression of an idea) that Executive creates or contributes to United Therapeutics in the course of his employment hereunder will be created solely by Executive, will be original to Executive, and

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will be free of any third party claims or interests.  Executive has not and hereby does not transfer any Intellectual Property rights owned or held solely by Executive to the Company relating to periods prior to the date of this Agreement and retains all rights to same provided, however, that Executive acknowledges that Intellectual Property rights that he created as an employee of the United Therapeutics Corporation prior to the date of this Agreement, and not otherwise previously assigned or transferred prior to the date of this Agreement are solely owned by the Company as a work made for hire.

(d)       Use .  United Therapeutics and its respective successors, licensees, and assigns shall have the sole and exclusive right to practice, or to make, use or sell products, processes or services derived from any discoveries or creations within the scope of this Agreement, whether or not patentable or copyrightable under the laws of any jurisdiction, or protected by the trade secret laws of any jurisdiction.

(e)       Infringement Actions .  In the event that United Therapeutics shall bring an infringement suit against any third parties or shall be sued by any third parties as a result of Executive’s authorship or creation, including without limitation any addition and/or modification of the aforementioned items of Confidential Information, Executive agrees to cooperate reasonably without charge to United Therapeutics, but at its request and expense, in defending against or prosecuting any such suit.  This right shall be cumulative to any other rights of United Therapeutics hereunder.

10.          Obligation of Confidentiality and Non-Competition .

(a)           Executive agrees that Executive has a fiduciary duty to the Company and that Executive shall hold in confidence and shall not, except in the course of performing Executive’s employment obligations or pursuant to written authorization from the Company, at any time during or for three years after termination of Executive’s relationship with the Company knowingly (a) directly or indirectly reveal, report, publish, disclose or transfer the Confidential Information or any part thereof to any person or entity; (b) use any of the Confidential Information or any part thereof for any purpose other than for the benefit of the Company; (c) assist any person or entity other than the Company to secure any benefit from the Confidential Information or any part thereof or (d) solicit (on Executive’s behalf or on behalf of any third party) any employee of the Company for the purpose of providing services or products which Executive is prohibited from providing hereunder.

(b)           Executive agrees that all Confidential Information, as defined below, shall belong exclusively and without any additional compensation to the Company.  For the purposes of this Agreement, “Confidential Information” shall mean each of the following:  (a) any information or material proprietary to the Company or designated as confidential either orally or in writing by the Company; and (b) any information not generally known by non- Company personnel; and (c) any information which Executive should know the Company would not care to have revealed to others or used in competition with the Company; and (d) any information which Executive made or makes, conceived or conceives, developed or develops or obtained or obtains knowledge or access through or as a result of Executive’s relationship with the Company (including information received, originated,

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discovered or developed in whole or in part by Executive) from the initial date of Executive’s employment with the Company.

(c)           Executive agrees not to accept employment from, nor render services in any capacity for, nor have any other business relationships with, nor engage in any business activity in which it would be useful or helpful to Executive or others with whom he is associated for Executive to use or disclose Confidential Information of the Company, with a “Competing Organization”, meaning any person or organization which is engaged in, or about to become engaged in, research on, or development, production, marketing, leasing, selling, licensing or servicing of, a Competing Product.  Competing Organizations may include, but are not necessarily limited to, Gilead Sciences, Inc., Actelion Ltd, Pfizer, Inc., Encysive Pharmaceuticals, Inc., Eli Lilly and Company and any other company that develops or markets any subsequently approved therapy for the treatment of pulmonary arterial hypertension, for a period of one (1) year following Executive’s last receipt of compensation from the Company, whether the termination of Executive’s employment by either party was with or without Cause. As used in this Agreement, a “Competing Product” means any product, system or service, in existence or under development, of any person or organization other than United Therapeutics which is the same as or similar to, and competes with, a product, process, system or service upon which Executive worked (in either a sales or a non-sales capacity) during the last three years of his or her employment by United Therapeutics or about which Executive acquired Confidential Information in the course of his or her employment with United Therapeutics.  Competing Products may include, but are not necessarily limited to, Flolan, Ventavis, Tracleer, Revatio, Thelin and Letairis, and other subsequently approved therapies for the treatment of pulmonary arterial hypertension. The parties acknowledge that the Company’s business after the date of this Agreement may evolve into other or additional areas and activities.  Executive and the Company agree that the terms of this Section 10(c) relating to non-competition are reasonable in scope and length and are necessary for the protection of the Company.  In the event that a court finds the scope of this provision to be unreasonably broad or if the length of time of this provision is found to be unreasonably long, an arbitrator or court, as applicable, shall narrow the scope or shorten the length of time to the extent required to render the provision reasonable and enforceable and shall enforce the provision as so narrowed.

(d)           While employed by the Company and for a period of one (1) year following Executive’s last receipt of compensation from the Company, whether the termination of Executive’s employment by either party was with or without Cause, the Executive will not (i) hire, induce, attempt to hire, assist in hiring, or cause to be hired, directly or indirectly, by another person or organization, any person who was an employee of the Company, and (ii) identify, or furnish any information about, any other employee of the Company to any other person or organization for the purpose of assisting or facilitating the hiring efforts of such other person or organization.

11.          Miscellaneous .

(a)           Entire Agreement .  This Agreement contains the entire agreement between the parties hereto relating to the subject matter hereof, and this Agreement

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supersedes all prior understandings and agreements, whether oral or written, relating to the employment of the Executive by the Company.

(b)           Assignment .  This Agreement shall not be assignable or otherwise transferable by either party hereto, but any amounts owing to Executive upon the Executive’s death shall inure to the benefit of the Executive’s heirs, legatees, legal representatives, executor or administrator.  Notwithstanding the foregoing, this Agreement applies with the prior written consent of the Executive, which consent shall not be unreasonably withheld.  This Agreement shall be binding upon and shall inure to the benefit of the parties hereto and any such respective heirs, legatees, executors, administrators, representatives, successors and assigns.

(c)           Notices .  All notices, demands, requests or other communications which may be, or are required to be given, served or sent by any party to any party pursuant to this Agreement shall be in writing and shall be mailed by first class, registered or certified mail, return receipt requested, postage prepaid, or transmitted by hand delivery, telegram or telex and addressed as follows:

(d)           Amendment; Waiver .  This Agreement shall not be amended, altered, modified or discharged except by an instrument in writing duly executed by the Executive and the Company.  Neither the waiver by the parties hereto of a breach of, or default under, any of the provisions of this Agreement, nor the failure of either of the parties, on one or more occasions, to enforce any of the provisions of this Agreement or to exercise any right or privilege hereunder, shall thereafter be construed as a waiver of any such provisions, rights or privileges hereunder.

(e)           Severability .  The invalidity or unenforceabilty of any provision or provisions of this Agreement shall not affect the validity or enforceability of any other provisions of this Agreement, which shall remain in full force and effect.

(f)            Applicable Law .  This Agreement and the rights and obligations of the parties under this Agreement shall be construed, interpreted and enforced in accordance with the laws of the State of Maryland, exclusive of the choice-of-laws rules thereunder.  The parties hereby irrevocably consent and submit to the exclusive jurisdiction of the courts located in the State of Maryland in connection with any suit, action or other proceeding concerning the interpretation or enforcement of this Agreement.  Each party waives and agrees not to assert any defense that such courts lack jurisdiction, venue is improper, inconvenient forum or otherwise.

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(g)           Survival .  It is the express intention and agreement of the parties hereto that the provisions of Sections 7(e), 8, 9, 10 and 11 hereof shall survive the termination of employment of the Executive.  In addition, all obligations of the Company to make payments hereunder shall survive any termination of this Agreement on the terms and conditions set forth.

(h)           Execution .  To facilitate execution, this Agreement may be executed in as many counterparts as may be required; and it shall not be necessary that the signatures of, or on behalf of, each party, or that the signatures of all persons required to bind any party, appear on each counterpart; but it shall be sufficient that the signature of, or on behalf of, each party, or that the signatures of the persons required to bind any party, appear on one or more of the counterparts.  All counterparts shall collectively constitute a single agreement.  It shall not be necessary in making proof of this Agreement to produce or account for more than a number of counterparts containing the respective signatures of, or on behalf of, all of the parties hereto.

IN WITNESS WHEREOF, the undersigned have duly executed this Agreement, or have caused this Agreement to be duly executed on their behalf, as of the date first above written.

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Exhibit 10.2

CHANGE IN CONTROL SEVERANCE AGREEMENT

This Change in Control Severance Agreement (the “Agreement”) is made and entered into by and between Michael Benkowitz (the “Employee”) and United Therapeutics Corporation, a Delaware corporation (the “Company”), effective as of February 14, 2012 (the “Effective Date”).

RECITALS

A.                                     Employee is a key member of the executive and management team of the Company or an Affiliate.

B.                                     The Company’s Board of Directors has approved a Change in Control Severance Program, consisting of the Change in Control Severance Plan and agreements such as this Agreement with certain individual employees, in order to provide severance protection to Employee in the event Employee’s employment terminates in specified circumstances within one year following a Change in Control in order to (i) motivate Employee to drive business success independent of the possible occurrence of a Change in Control and (ii) reduce distractions associated with a potential Change in Control, and maximize shareholder value by retaining Employee through the closing of a Change in Control.

In consideration of the mutual covenants herein contained, and in consideration of the continuing employment of Employee by the Company, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties agree as follows.

Section 1.                                            Severance Benefits .  If Employee’s employment with the Company and its Affiliates (i) is involuntarily Terminated by the Company and its Affiliates within one year following a Change in Control other than due to Cause, Total Disability or death, or (ii) is Terminated by Employee for Good Reason within one year following a Change in Control, subject to Employee executing a release of claims substantially in the form attached as Exhibit A within forty-five (45) days following such Termination (and not revoking such release), Employee shall be entitled to the following:

(a)                                  Cash Severance Pay .  Employee shall receive a lump sum cash payment equal to two (2) times the sum of (A) the Base Salary and (B) the Bonus Amount

(b)                                  Medical Continuation .  Employee and Employee’s spouse and dependents (each as defined under the applicable plan) shall receive Company-paid medical and dental insurance coverages for twenty-four (24) months at the same benefit level as provided to Employee immediately prior to the Change in Control (which such period shall be treated as “alternative coverage” for purposes of COBRA).

(c)                                   Outplacement Benefits .  Employee shall be entitled to receive outplacement benefits with a value of $10,000, to be used over the six months following Employee’s Termination (which such benefits shall be administered in compliance with Treasury Regulation section 1.409A-1(b)(9)(v)).

(d)                                  Accrued Benefits .  Employee shall receive any unpaid Base Salary through the date of Termination and any bonus unpaid as of the date of Employee’s Termination for any previously completed fiscal year of the Company.  In addition, Employee shall be entitled to prompt reimbursement of any unreimbursed expenses properly incurred by Employee in accordance with Company policies prior to the date of Employee’s Termination.  Employee shall also receive such other compensation (including any stock options or other equity-related payments (including, without limitation, any share tracking awards)) and benefits, if any, to which Employee may be entitled from time to time pursuant to the terms and conditions of Employee compensation, incentive, equity, benefit or fringe benefit plans, policies or programs of the Company, other than any Company severance policy.

Section 2.                                            Form and Time of Payment; Payment in Lieu of Other Severance Benefits .  The cash severance pay benefits payable to Employee under Section 1(a) shall be paid to Employee in a single lump sum less applicable withholdings within the later of (i) 15 business days after Employee’s date of Termination or (ii) the expiration of the revocation period, if applicable, under the Release, but in all events no later than March 15 of the year following the year in which Employee’s Termination of Employment occurs.  The cash severance benefits provided pursuant to Section 1(a) hereof are in lieu of any cash severance benefits (but, not for the avoidance of doubt, in lieu of any equity-related payments (including, without limitation, share tracking awards) or payments under any tax-qualified or nonqualified retirement plan) that may be payable to Employee pursuant to any agreement between Employee and the Company or any other plan, program or arrangement of the Company and its Affiliates (unless the cash severance benefits under such agreement, plan, program or arrangement are more favorable in the aggregate to Employee, in which case such benefits shall be provided in lieu of the benefits hereunder). Notwithstanding the foregoing, to the extent the cash severance benefits under Section 1(a) would constitute an impermissible substitution within the meaning of Treasury Regulation section 1.409A-3(f) and payment of such benefits in the manner described herein would result in a violation of Section 409A of the Code, such benefits shall be paid on the same schedule as the benefits for which they are deemed to substitute.

Section 3.                                            Definitions .  Unless the context clearly indicates otherwise, when used in this Agreement:

(a)                                  “ Affiliate ” means, with respect to any entity, any other corporation, organization, association, partnership, sole proprietorship or other type of entity, whether incorporated or unincorporated, directly or indirectly controlling or controlled by or under direct or indirect common control with such entity.

(b)                                  “ Base Salary ” means Employee’s annual rate of base salary in effect on the date of Employee’s Termination of Employment (or, if higher, on the date of the Change in Control), determined in each case prior to reduction for any employee-elected salary reduction contributions made to a Company-sponsored non-qualified deferred compensation plan or a Company-sponsored plan pursuant to Section 401(k) or 125 of the Code, and excluding bonuses, overtime, allowances, commissions, deferred compensation payments and any other extraordinary remuneration.

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(c)                                   “ Board ” means the board of directors of the Company.

(d)                                  “ Bonus Amount ” means the highest of (i) the cash bonus payable to Employee for the year immediately preceding the year in which the Change in Control occurs, (ii) the cash bonus payable to Employee for the year immediately preceding the year in which Employee’s employment Terminates, or (iii) Employee’s Target Bonus.

(e)                                   “ Cause ” means (i) any act of personal dishonesty taken by Employee in connection with his or her responsibilities as an employee and intended to result in substantial personal enrichment of Employee; (ii) Employee’s conviction of a felony; (iii) an act by Employee which constitutes willful or gross misconduct and which is demonstrably and materially injurious to the Company; or (iv) continued substantial willful violations by Employee of Employee’s employment duties after there has been delivered to Employee a written demand for performance from the Company which specifically sets forth the factual basis for the Company’s belief that Employee has not substantially performed his or her duties.

(f)                                    “ Change in Control ” means, and shall be deemed to have occurred:

(i)                                      if any person or group (as used in Section 13(d) of the Exchange Act) (other than the Company, any trustee or other fiduciary holding securities under an employee benefit plan of the Company, or any company owned, directly or indirectly, by the stockholders of the Company in substantially the same proportions as their ownership of stock of the Company) becomes the “beneficial owner” (as defined in Rule 13d-3 under the Exchange Act) of securities of the Company representing more than 30% of (a) the shares of the Company’s common stock then outstanding or (b) the combined voting power (other than in the election of directors) of all voting securities of the Company then outstanding;

(ii)                                   if, during any period of 24 consecutive months, individuals who at the beginning of such period constituted the Board, and any director whose election or nomination for election by the Company’s stockholders was approved by a vote of at least two-thirds (2/3) of the directors then still in office who either were directors at the beginning of the period or whose election or nomination for election was previously so approved (the “Incumbent Board”), cease for any reason (other than death or disability) to constitute at least a majority thereof;

(iii)                                upon the consummation of a reorganization, merger, statutory share exchange or consolidation or similar transaction involving the Company or any of its subsidiaries unless, following such event, (A) all or substantially all of the individuals and entities that were the beneficial owners of the Company’s common stock or the combined voting power of all voting securities of the Company immediately prior to such transaction beneficially own, directly or

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indirectly, more than 50% of the then-outstanding shares of common stock (or, for a non-corporate entity, equivalent securities) and the combined voting power of the then-outstanding voting securities entitled to vote generally in the election of directors (or, for a non-corporate entity, equivalent governing body), as the case may be, of the entity resulting from such transaction (including, without limitation, an entity that, as a result of such transaction, owns the Company either directly or through one or more subsidiaries) in substantially the same proportions as their ownership immediately prior to such transaction of the Company’s common stock or voting securities, as the case may be, (B) no person (excluding any corporation resulting from such transaction or any employee benefit plan (or related trust) of the Company or such corporation resulting from such transaction) beneficially owns, directly or indirectly, 30% or more of, respectively, the then-outstanding shares of common stock of the corporation resulting from such transaction or the combined voting power of the then-outstanding voting securities of such corporation, except to the extent that such ownership existed prior to the transaction, and (C) at least a majority of the members of the board of directors (or, for a non-corporate entity, equivalent governing body) of the entity resulting from such transaction were members of the Incumbent Board at the time of the execution of the initial agreement or of the action of the Board providing for such transaction; or

(iv)                               upon the complete liquidation of the Company or the sale or disposition by the Company of all or substantially all of the Company’s assets, other than a liquidation of the Company into a wholly-owned subsidiary.

(g)                                   “ COBRA ” means the Consolidated Omnibus Budget Reconciliation Act of 1985, as amended.

(j)                                     “ Good Reason ” means any of the following actions upon or after a Change in Control, without Employee’s express prior written approval, other than due to Employee’s Total Disability or death: (i) (A) a material adverse change in Employee’s status, title, position or responsibilities (including reporting responsibilities from Employee’s status, title, position or responsibilities as in effect immediately prior to the Change in Control); (B) the assignment to Employee of any duties or responsibilities which are materially inconsistent with Employee’s status, title, position or responsibilities as in effect immediately prior to the Change in Control; or (C) any removal of Employee from or failure to reappoint or reelect Employee to any of the offices or positions held by Employee immediately prior to the Change in Control, except in the case of (A), (B) or

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(C), in connection with the Termination of Employee’s employment for Cause, as a result of Employee’s Total Disability or death, or by Employee other than for Good Reason; (ii) a reduction in Employee’s Base Salary or any failure to pay Employee any compensation or benefits to which Employee is entitled within five days of the date due; (iii) a reduction in Employee’s annual cash bonus opportunity or equity-type incentive opportunity; (iv) the Company requiring Employee to relocate to any place outside a 50 mile radius of the location serving as Employee’s principal work site immediately prior to the Change in Control, except for reasonably required travel on the business of the Company or an Affiliate which is not materially greater than such travel requirements in effect immediately prior thereto; (v) the failure by the Company to continue in effect employee benefits for Employee no less favorable in the aggregate as in effect immediately prior to the Change in Control; (vi) any material breach by the Company of any provision of an agreement between the Company and Employee; or (vii) the failure of the Company to obtain an agreement from any successors and assigns to assume and agree to perform the obligations created under this Agreement.  With respect to (i) through (vi) above, Good Reason shall not be deemed to have occurred unless Employee shall have notified the Company in writing of his or her intent to resign for Good Reason within thirty (30) days following occurrence of the event constituting Good Reason and the Company shall not have cured the grounds for Good Reason within ten (10) days following the provision of such notice.

(k)                                  “ Release ” means a waiver and release to be signed by Employee substantially in the form attached hereto as Exhibit A (which Release is not revoked by Employee).

(l)                                      “ Target Bonus ” means the greater of (i) Employee’s annual cash target bonus in effect immediately prior to the date a Change in Control occurs, or (ii) Employee’s annual cash target bonus in effect as of the date his or her employment Terminates, in either case assuming full attainment of companywide milestones,

(m)                              “ Terminate ” or “ Termination of Employment ” means Employee’s “separation from service” from the Company and its Affiliates, as determined pursuant to Section 409A of the Code.

(n)                                  “ Total Disability ”  means that, in the Company’s reasonable judgment, either (1) Employee has been unable to perform Employee’s duties because of a physical or mental impairment for 80% or more of the normal working days during six consecutive calendar months or 50% or more of the normal working days during twelve consecutive calendar months, or (2) Employee has become totally and permanently incapable of performing the usual duties of his employment with the Company on account of a physical or mental impairment.

Section 4.                                            Limitation of Certain Payments .

(a)                                  In the event the Company reasonably determines, based upon the advice of the independent public accountants for the Company, that part or all of the consideration,

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compensation or benefits to be paid to Employee under this Agreement constitute“ parachute payments ” under Section 280G(b)(2) of the Code, as amended, then, if the aggregate present value of such parachute payments, singularly or together with the aggregate present value of any consideration, compensation or benefits to be paid to Employee under any other plan, arrangement or agreement which constitute “ parachute payments ” (collectively, the “ Parachute Amount ”) exceeds 2.99 times Employee’s “ base amount ”, as defined in Section 280G(b)(3) of the Code (the “ Employee Base Amount ”), the amounts constituting “ parachute payments ” which would otherwise be payable to or for the benefit of Employee shall be reduced to the extent necessary so that the Parachute Amount is equal to 2.99 times Employee Base Amount (the “ Reduced Amount ”); provided that such amounts shall not be so reduced if Employee determines, based upon the advice of an independent nationally recognized public accounting firm (which may, but need not be the independent public accountants of the Company), that without such reduction Employee would be entitled to receive and retain, on a net after tax basis (including, without limitation, any excise taxes payable under Section 4999 of the Code), an amount which is greater than the amount, on a net after tax basis, that Employee would be entitled to retain upon his receipt of the Reduced Amount.  External accountants’ advice contemplated by this Section 4(a), and fees and expenses incurred in connection therewith, shall be the sole responsibility of the Company.

(b)                                  If the determination made pursuant to clause (a) of this Section 4 results in a reduction of the payments that would otherwise be paid to Employee except for the application of clause (a) of this Section 4, the amounts payable or benefits to be provided to Employee shall be reduced such that the reduction of compensation to be provided to Employee is minimized.  In applying this principle, the reduction shall be made in a manner consistent with the requirements of Section 409A of the Code, and where two economically equivalent amounts are subject to reduction but payable at different times, such amounts shall be reduced on a pro rata basis (but not below zero).

(c)                                   As a result of the uncertainty in the application of Section 280G of the Code at the time of a determination hereunder, it is possible that payments will be made by the Company which should not have been made under clause (a) of this Section 4 (“ Overpayment ”) or that additional payments which are not made by the Company pursuant to clause (a) of this Section 4 should have been made (“ Underpayment ”).  In the event that there is a final determination by the Internal Revenue Service, or a final determination by a court of competent jurisdiction, that an Overpayment has been made, any such Overpayment shall be repaid by Employee to the Company together with interest at the applicable Federal rate provided for in Section 7872(f)(2) of the Code.  In the event that there is a final determination by the Internal Revenue Service, a final determination by a court of competent jurisdiction or a change in the provisions of the Code or regulations pursuant to which an Underpayment arises under this Agreement, any such Underpayment shall be promptly (and in all events no later than December 31 of the year following the year in which the applicable tax is remitted) paid by the Company to or for the benefit of Employee, together with interest at the applicable Federal rate provided for in Section 7872(f)(2) of the Code.

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Section 5.                                            Successors .  Any successor to the Company (whether direct or indirect and whether by purchase, lease, merger, consolidation, liquidation or otherwise) to all or substantially all of the Company’s business and/or assets shall assume the obligations under this Agreement and agree expressly to perform the obligations under this Agreement in the same manner and to the same extent as the Company would be required to perform such obligations in the absence of a succession.  The terms of this Agreement and all of Employee’s rights hereunder shall inure to the benefit of, and be enforceable by, Employee’s personal or legal representatives, executors, administrators, successors, heirs, distributees, devisees and legatees.

Section 6.                                            Notice .  Notices and all other communications contemplated by this Agreement shall be in writing and shall be deemed to have been duly given when personally delivered or when mailed by U.S. registered or certified mail, return receipt requested and postage prepaid.  Mailed notices to Employee shall be addressed to Employee at the home address which Employee most recently communicated to the Company in writing.  In the case of the Company, mailed notices shall be addressed to its corporate headquarters, and all notices shall be directed to the attention of its General Counsel.

Section 7.                                            Miscellaneous Provisions .

(a)                                  Waiver .  No provision of this Agreement shall be modified, waived or discharged unless the modification, waiver or discharge is agreed to in writing and signed by Employee and by an authorized officer of the Company (other than Employee).  No waiver by either party of any breach of, or of compliance with, any condition or provision of this Agreement by the other party shall be considered a waiver of any other condition or provision or of the same condition or provision at another time.

(b)                                  Entire Agreement .  This Agreement constitutes the entire understanding between the parties with respect to the matters addressed herein, superseding all negotiations, prior discussions and agreements, written or oral, concerning such matters (but excluding, for the avoidance of doubt, obligations to Employee under any stock option, stock award or agreements or obligations under any pension, deferred compensation or retention plan (including, without limitation, any share tracking awards)).  In addition, any noncompetition and nonsolicitation covenants in any agreement between Employee and the Company shall continue to apply in accordance with their terms.

(c)                                   Choice of Law .  Except to the extent preempted by federal law, this Agreement shall be governed and construed in accordance the laws of the State of Delaware, without regard to principles of conflicts of laws.

(d)                                  Severability .  If any term or provision of this Agreement or the application thereof to any circumstance shall, in any jurisdiction and to any extent, be invalid or unenforceable, such term or provision shall be ineffective as to such jurisdiction to the extent of such invalidity or unenforceability without invalidating or rendering unenforceable the remaining terms and provisions of this Agreement or the application of such terms and provisions to circumstances other than those as to which it is held invalid or unenforceable, and a suitable and equitable term or provision shall be substituted

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therefor to carry out, insofar as may be valid and enforceable, the intent and purpose of the invalid or unenforceable term or provision.

(e)                                   No Assignment of Benefits .  The rights of Employee to payments or benefits under this Agreement shall not be made subject to option or assignment, either by voluntary or involuntary assignment or by operation of law, including (without limitation) bankruptcy, garnishment, attachment or other creditor’s process, and any action in violation of this subsection  shall be void, provided Employee’s estate shall be entitled to receive any benefits that have become payable, but which have not been paid in accordance with Section 2 above.

(f)                                    Employment Taxes .  Any payments made pursuant to this Agreement will be reported on Form W-2 and shall be subject to withholding of applicable income and employment taxes.

(g)                                   Counterparts .  This Agreement may be executed in counterparts, each of which shall be deemed an original, but all of which together will constitute one and the same instrument.

(h)                                  Confidentiality of Agreement .  Employee shall keep strictly confidential all the terms and conditions, including amounts, in this Agreement and shall not disclose them to any person other than Employee’s immediate family members, Employee’s legal or financial advisor, or governmental officials who seek such information in the course of their official duties, unless compelled by law to do so.

(i)                                      Not An Employment Agreement .  Nothing in this Agreement shall give Employee the right to be retained in the employ or other service of the Company or its Affiliates to interfere with the right of the Company and its Affiliates to discharge Employee in accordance with any employment agreement.

(j)                                     No Duty to Mitigate .  Employee shall not be required to mitigate the amount of any benefit contemplated by this Agreement (whether by seeking new employment or in any other manner), nor shall any such benefit be reduced by any earnings or benefits that Employee may receive from any other source.

(k)                                  Waiver of Plan Benefits .  Employee hereby waives participation in the United Therapeutics Corporation Change in Control Severance Plan and acknowledges that no benefits shall be paid to Employee pursuant to such Plan.

[Signature page follows]

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IN WITNESS WHEREOF, each of the parties has executed this Agreement, in the case of the company by its duly authorized officer, as of the day and year first above written.

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EXHIBIT A

WAIVER AND RELEASE

For and in consideration of the payments and other benefits due to             (“Employee”) pursuant to the Change in Control Severance Agreement between Employee and United Therapeutics Corporation dated as of            , 2012 (the “CIC Agreement”), and for other good and valuable consideration, Employee hereby agrees, for Employee, Employee’s spouse and child or children (if any), Employee’s heirs, beneficiaries, devisees, executors, administrators, attorneys, personal representatives, successors and assigns, to forever waive and release all known and unknown claims and causes of action, arising on or before the date of Employee’s execution of this  Waiver and Release, against United Therapeutics Corporation (the “Company”) or any of its divisions, affiliates, subsidiaries, parents, branches, predecessors, successors, assigns, and, with respect to such entities, their officers, directors, trustees, employees, agents, shareholders, administrators, general or limited partners, representatives, attorneys, insurers and fiduciaries, past, present and future (the “Released Parties”), including, but not limited to, all such claims and causes of action which in any way pertain to Employee’s employment with and/or termination of employment from the Company, all allegations of employment discrimination, and/or all other occurrences whatsoever, including but not limited to the Age Discrimination in Employment Act, Title VII of the Civil Rights Act of 1964, as amended, 42 U.S.C. Section 2000e et. seq., the Fair Labor Standards Act, as amended, 29 U.S.C. Section 201 et. seq., the Americans with Disabilities Act, as amended, 42 U.S.C. Section 12101 et. seq., the Reconstruction Era Civil Rights Act, as amended, 42 U.S.C. Section 1981 et. seq., the Rehabilitation Act of 1973, as amended, 29 U.S.C. Section 701 et. seq., the Family and Medical Leave Act of 1993, 29 U.S.C. Section 2601 et. seq., the False Claims Act, 31 U.S.C Section 3729 et. seq. and any and all state or local laws regarding employment discrimination and/or federal, state or local laws of any type or description regarding employment, including but not limited to any claims arising from or derivative of Employee’s employment with the Company and its Affiliates, as well as any and all such claims under state contract or tort law.

Employee has read this Waiver and Release carefully, acknowledges that Employee has been given at least forty-five (45) days to consider all of its terms and has been advised to consult with an attorney and any other advisors of Employee’s choice prior to executing this Waiver and Release, and Employee fully understands that by signing below Employee is voluntarily giving up any right which Employee may have to sue or bring any other claims against the Released Parties, including any rights and claims under the Age Discrimination in Employment Act.  Employee also understands that Employee has a period of seven (7) days after signing this Waiver and Release within which to revoke his or her agreement, and that neither the Company nor any other person is obligated to make any payments or provide any other benefits to Employee pursuant to the CIC Agreement until eight (8) days have passed since Employee’s signing of this Waiver and Release without Employee’s signature having been revoked other than any accrued obligations or other benefits payable pursuant to the terms of the Company’s normal payroll practices or employee benefit plans.  Finally, Employee has not been forced or pressured in any manner whatsoever to sign this Waiver and Release, and Employee agrees to all of its terms voluntarily.

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Notwithstanding anything else herein to the contrary, this Waiver and Release shall not affect: (i) the Company’s obligations under any compensation or employee benefit plan, program or arrangement (including, without limitation, obligations to Employee under any stock option, stock award or agreements or obligations under any pension, deferred compensation or retention plan (including, without limitation, any share tracking awards)) provided by the Affiliated Entities where Employee’s compensation or benefits are intended to continue or Employee is to be provided with compensation or benefits, in accordance with the express written terms of such plan, program or arrangement, beyond the date of Employee’s termination; or (ii) rights to indemnification or liability insurance coverage Employee may have under the by-laws of the Company or applicable law.

In addition, excluded from this Waiver and Release are any claims which by law cannot be waived, including but not limited to the right to file a charge with or participate in an investigation by the Equal Employment Opportunity Commission (“EEOC”).  Employee does, however, hereby waive all rights to recover any money, benefits or reinstatement should the EEOC or any other agency or individual pursue any claims on Employee’s behalf.

This Waiver and Release is final and binding and may not be changed or modified except in a writing signed by both parties.

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