United Therapeutics officer plans $4.1M stock sale

Officer Paul Mahon files a Rule 144 notice to sell 8,300 UTHR shares after option exercise, following similar sales over the prior three months.

Rhea-AI Filing Summary

UNITED THERAPEUTICS CORPORATION (UTHR) has an officer, Paul Mahon, filing a notice of proposed sale of restricted or control common stock under Rule 144. The notice covers 8,300 shares of common stock, with an aggregate market value of $4,129,607.73, relative to 42,890,692 shares outstanding as of September 17, 2026.

The filing notes the shares are tied to a stock option exercise for cash on September 17, 2026, with Morgan Stanley Smith Barney LLC listed as the broker. Mahon also reports a pattern of prior Rule 144 sales, each for 8,300 shares, on six dates between June 18, 2026 and September 3, 2026, with reported aggregate prices ranging from about $4.00 million to $4.59 million per sale.

Key Figures

Shares to be sold under Rule 144: 8,300 shares Aggregate market value of shares to be sold: $4,129,607.73 Shares outstanding: 42,890,692 shares +3 more

6 metrics

Shares to be sold under Rule 144 8,300 shares Common stock covered by the notice as of September 17, 2026

Aggregate market value of shares to be sold $4,129,607.73 8,300 shares of common stock as of September 17, 2026

Shares outstanding 42,890,692 shares United Therapeutics common stock outstanding as of September 17, 2026

Recent sale on September 3, 2026 8,300 shares for $4,000,836.55 Common stock sold by Paul Mahon during the past three months

Recent sale on August 20, 2026 8,300 shares for $4,342,078.81 Common stock sold by Paul Mahon during the past three months

Recent sale on July 2, 2026 8,300 shares for $4,586,274.56 Common stock sold by Paul Mahon during the past three months

Key Terms

Rule 144, aggregate market value, stock option exercise, restricted or control securities

4 terms

Rule 144 regulatory

"See the definition of "person" in paragraph (a) of Rule 144."

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

aggregate market value financial

"Common ... 8300 | 4129607.73 | 42890692 | 09/17/2026"

Aggregate market value is the combined price you would pay to buy all outstanding shares of a company or all companies in a group at current market prices — essentially the sum of each stock’s market capitalization. It matters to investors because it shows the overall size and weight of an investment or sector (like the total cost to buy every piece of a puzzle), helps compare scale across companies or markets, and influences index composition and risk exposure.

stock option exercise financial

"Common | 09/17/2026 | Stock Option Exercise | Issuer"

A stock option exercise is the act of using a previously granted right to buy shares of a company's stock at a specific, predetermined price by paying that price and receiving the shares. It matters to investors because exercising changes who owns the shares (which can dilute existing ownership), can trigger taxable events and shift potential gains or losses, and affects voting power and the company’s outstanding share count—like turning a voucher into an actual product that becomes part of circulating supply.

restricted or control securities regulatory

"Name of Person for Whose Account the Securities are To Be Sold"

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What does the Form 144 filing mean for UNITED THERAPEUTICS (UTHR)?

The filing reports that an officer, Paul Mahon, has given notice under Rule 144 of an intent to sell 8,300 shares of UTHR common stock after a stock option exercise, through a broker. It is a disclosure of a potential sale of restricted or control securities.

How many UNITED THERAPEUTICS (UTHR) shares are covered by this Form 144?

The notice covers 8,300 shares of UNITED THERAPEUTICS common stock. These shares have an aggregate market value of $4,129,607.73 as of September 17, 2026, according to the filing.

How many UNITED THERAPEUTICS (UTHR) shares were outstanding as of the filing date?

Shares of UNITED THERAPEUTICS common stock outstanding were 42,890,692 shares as of September 17, 2026. This figure is provided as context in the Form 144 filing and is not the amount being sold.

What recent sales by Paul Mahon in UTHR stock are disclosed?

The filing lists six sales of 8,300 shares each between June 18, 2026 and September 3, 2026, with aggregate sale prices including $4,494,840.93, $4,586,274.56, and $4,429,512.51. All were sales of UNITED THERAPEUTICS common stock.

How is the planned UTHR share sale by Paul Mahon related to stock options?

The securities to be sold are linked to a stock option exercise on September 17, 2026. The filing states the transaction type as “Stock Option Exercise” with consideration in cash, and the shares are then eligible for sale under Rule 144.

Which broker is handling the potential UTHR stock sale under this Form 144?

The broker named is Morgan Stanley Smith Barney LLC Executive Financial Services, at 1 New York Plaza, for the 8,300 shares of UNITED THERAPEUTICS common stock covered by this Rule 144 notice.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 09/17/2026 - 04:20 PM Accepted by SEC EDGAR 09/17/2026 - 04:19 PM Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001231589
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	UNITED THERAPEUTICS CORPORATION
SEC File Number	000-26301
Address of Issuer	1000 SPRING STREET SILVER SPRING MARYLAND 20910
Phone	(301) 608-9292
Name of Person for Whose Account the Securities are To Be Sold	PAUL MAHON
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Officer

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common	Morgan Stanley Smith Barney LLC Executive Financial Services 1 New York Plaza 8th Floor New York NY 10004	8300	4129607.73	42890692	09/17/2026	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common	09/17/2026	Stock Option Exercise	Issuer			8300	09/17/2026	Cash

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
PAUL MAHON 1000 SPRING STREET SILVER SPRING MD 20910	Common	09/03/2026	8300	4000836.55
PAUL MAHON 1000 SPRING STREET SILVER SPRING MD 20910	Common	08/20/2026	8300	4342078.81
PAUL MAHON 1000 SPRING STREET SILVER SPRING MD 20910	Common	08/06/2026	8300	4291512.51
PAUL MAHON 1000 SPRING STREET SILVER SPRING MD 20910	Common	07/16/2026	8300	4429637.79
PAUL MAHON 1000 SPRING STREET SILVER SPRING MD 20910	Common	07/02/2026	8300	4586274.56
PAUL MAHON 1000 SPRING STREET SILVER SPRING MD 20910	Common	06/18/2026	8300	4494840.93

144: Remarks and Signature

Remarks
Date of Notice	09/17/2026
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	08/11/2025
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	/s/ Paul A. Mahon
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)