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                            July 14, 2022

       Martine Rothblatt
       Chief Executive Officer
       United Therapeutics Corporation
       1040 Spring Street
       Silver Spring, Maryland 20910

                                                        Re: United Therapeutics
Corporation
                                                            Form 10-K for the
Fiscal Year Ended December 31, 2021
                                                            Filed February 24,
2022
                                                            File No. 000-26301

       Dear Mr. Rothblatt:

               We have limited our review of your filing to the financial
statements and related
       disclosures and have the following comment. In our comment, we may ask
you to provide us
       with information so we may better understand your disclosure.

              Please respond to the comment within ten business days by
providing the requested
       information or advise us as soon as possible when you will respond. If
you do not believe our
       comment applies to your facts and circumstances, please tell us why in
your response.

                                                        After reviewing your
response to these comment, we may have additional comments.

       Form 10-K for the Fiscal Year Ended December 31, 2021

       Management's Discussion and Analysis of Financial Condition and Results
of Operations
       Research and Development , page 54

   1.                                                   We note that you have
multiple products in varying stages of development. Please revise
                                                        future filings to
provide more details about your research and development expenses for
                                                        each period presented,
including but not limited to by product/program as well as by the
                                                        nature of the expenses.
To the extent that you do not track expenses by product candidate,
                                                        please disclose as
such.
 Martine Rothblatt
United Therapeutics Corporation
July 14, 2022
Page 2

       In closing, we remind you that the company and its management are
responsible for the
accuracy and adequacy of their disclosures, notwithstanding any review,
comments, action or
absence of action by the staff.

       You may contact Christie Wong, Staff Accountant, at (202) 551-3684 or
Daniel Gordon,
Senior Advisor, at (202) 551-3486 with any questions.



FirstName LastNameMartine Rothblatt                       Sincerely,
Comapany NameUnited Therapeutics Corporation
                                                          Division of
Corporation Finance
July 14, 2022 Page 2                                      Office of Life
Sciences
FirstName LastName