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): November 7, 2011

UNITEDHEALTH GROUP INCORPORATED

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (952) 936-1300

N/A

(Former name or former address, if changed since last report.)

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:

On November 7, 2011, UnitedHealth Group Incorporated (the “Company”) agreed to sell (i) $400,000,000 aggregate principal amount of its 1.875% Notes due November 15, 2016 (the “2016 Notes”), (ii) $500,000,000 aggregate principal amount of its 3.375% Notes due November 15, 2021 (the “2021 Notes”), and (iii) $600,000,000 aggregate principal amount of its 4.625% Notes due November 15, 2041 (the “2041 Notes” and collectively with the 2016 Notes and the 2021 Notes, the “Notes”), pursuant to the Underwriting Agreement, dated November 7, 2011 (“Underwriting Agreement”), and the Pricing Agreement, dated November 7, 2011 (“Pricing Agreement”), both among the Company and Goldman, Sachs & Co., Morgan Stanley & Co. LLC, RBS Securities Inc., and U.S. Bancorp Investments, Inc., as representatives of the several underwriters listed on Schedule I of the Pricing Agreement.

The Notes were issued pursuant to that certain Indenture, dated as of February 4, 2008, between the Company and U.S. Bank National Association, as trustee (the “Indenture”), and (i) the Officers’ Certificate and Company Order, dated November 10, 2011, relating to the 2016 Notes, (ii) the Officers’ Certificate and Company Order, dated November 10, 2011, relating to the 2021 Notes, and (iii) the Officers’ Certificate and Company Order, dated November 10, 2011, relating to the 2041 Notes, in each case, pursuant to Sections 201, 301 and 303 of the Indenture.

The Notes were issued on November 10, 2011, and have been registered under the Securities Act of 1933, as amended, pursuant to a shelf registration statement on Form S-3, File No. 333-172235. The Company is filing this Current Report on Form 8-K to file with the Securities and Exchange Commission certain items related to the issuance of the Notes that are to be incorporated by reference into the above referenced registration statement.

The Underwriting Agreement is attached hereto as Exhibit 1.1. The Pricing Agreement is attached hereto as Exhibit 1.2. The Officers’ Certificates and Company Orders relating to the 2016 Notes, 2021 Notes and 2041 Notes, each including the respective form of Note, are attached hereto as Exhibit 4.1, Exhibit 4.2 and Exhibit 4.3, respectively.

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Signatures

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.

Date: November 10, 2011

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EXHIBIT INDEX

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