Item 8.01 Other Events

On September 1, 2009, United Therapeutics Corporation (the "Company") issued a press release announcing that the Company's Board of Directors approved a split of the Company's common stock to be effected in the form of a stock dividend, in which one share of common stock will be distributed for each share of common stock issued as of September 14, 2009 (the "Record Date") (whether outstanding or held in treasury) (the "Stock Dividend"). The distribution is scheduled to occur on September 22, 2009 to shareholders of record at the close of business on the Record Date.

In accordance with the First Amended and Restated Rights Agreement between the Company and The Bank of New York, as rights agent, dated as of June 30, 2008 (the "Rights Agreement"), each share of the Company's common stock is currently accompanied by one preferred share purchase right (a "Right"). Each Right entitles the holder to purchase a certain number of shares of the Company's Series A Junior Participating Preferred Stock, par value $0.01 per share (the "Preferred Stock"). Pursuant to Section 11(p) of the Rights Agreement, an adjustment to the number of one-thousandths of a share of Preferred Stock purchasable upon proper exercise of a Right will be required as a result of the Stock Dividend. Effective as of September 22, 2009, each outstanding share of common stock (including those shares issued in the Stock Dividend) will be accompanied by one Right and each outstanding Right will be adjusted to represent the right to purchase one-half of one one-thousandth of a share of Preferred Stock.

A copy of the press release announcing the Stock Dividend is attached hereto and furnished as Exhibit 99.1.

Item 9.01 Exhibits

(d) Exhibits

Exhibit No. Description of Exhibit
99.1 Press Release dated September 1, 2009

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