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)

October 5, 2012 (October 5, 2012)

COVENTRY HEALTH CARE, INC.

(Exact name of registrant as specified in its charter).

6720-B Rockledge Drive, Suite 700, Bethesda, Maryland 20817

(Address of principal executive offices) (Zip Code)

(301) 581-0600

(Registrant’s telephone number, including area code)

Not Applicable

(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 (see General Instruction A.2. below):

Item 8.01. Other Events.

Coventry Health Care, Inc. has been notified by Aetna Inc. (“Aetna”) that, as part of Aetna’s continuing cooperation with the U.S. Department of Justice (“DOJ”), Aetna will re-file its premerger notification with the DOJ and the U.S. Federal Trade Commission under the Hart-Scott-Rodino Antitrust Improvements Act of 1976 (the “HSR Act”) in connection with its proposed acquisition of Coventry. Based upon information provided by Aetna, Coventry expects that the notification will be re-filed on or before October 10, 2012, initiating a new waiting period under the HSR Act that will expire 30 days later, unless extended by a request for further information or terminated earlier. Aetna has also informed Coventry that Aetna has filed all material applications required for state regulatory approval of the acquisition of Coventry. Coventry continues to expect the transaction with Aetna to be completed in mid-2013.

In addition, the Coventry board of directors has fixed the close of business on October 15, 2012, as the record date for determination of the Coventry stockholders entitled to notice of, and to vote at, the Coventry special meeting regarding the proposed transaction or any adjournment or postponement thereof. The Coventry special meeting of stockholders is currently scheduled to be held on November 21, 2012 in Nashville, Tennessee.

Important Information For Investors And Stockholders

This communication does not constitute an offer to sell or the solicitation of an offer to buy any securities or a solicitation of any vote or approval. On September 21, 2012, Aetna filed with the Securities and Exchange Commission (“SEC”) a registration statement on Form S-4 containing a preliminary proxy statement/prospectus. The registration statement has not yet become effective. After the registration statement is declared effective by the SEC, Coventry will file with the SEC a definitive proxy statement/prospectus, and each of Aetna and Coventry will file other documents with respect to the proposed acquisition of Coventry and a definitive proxy statement/prospectus will be mailed to stockholders of Coventry. INVESTORS AND SECURITY HOLDERS OF COVENTRY ARE URGED TO READ THE PROXY STATEMENT/PROSPECTUS AND OTHER DOCUMENTS FILED OR THAT WILL BE FILED WITH THE SEC CAREFULLY AND IN THEIR ENTIRETY BECAUSE THEY CONTAIN OR WILL CONTAIN IMPORTANT INFORMATION. Investors and security holders may obtain free copies of the registration statement and the proxy statement/prospectus and other documents filed with the SEC by Aetna or Coventry through the website maintained by the SEC at http://www.sec.gov. Copies of the documents filed with the SEC by Aetna are available free of charge on Aetna’s internet website at http://www.aetna.com or by contacting Aetna’s Investor Relations Department at 860-273-8204. Copies of the documents filed with the SEC by Coventry are available free of charge on Coventry’s internet website at http://www.cvty.com or by contacting Coventry’s Investor Relations Department at 301-581-5717.

Aetna, Coventry, their respective directors and certain of their executive officers may be considered participants in the solicitation of proxies in connection with the proposed transaction. Information about the directors and executive officers of Coventry is set forth in its Annual Report on Form 10-K for the year ended December 31, 2011, which was filed with the SEC on February 28, 2012, its proxy statement for its 2012 annual meeting of stockholders, which was filed with the SEC on April 6, 2012, and its Current Report on Form 8-K, which was filed with the SEC on May 31, 2012. Information about the directors and executive officers of Aetna is set forth in its Annual Report on Form 10-K for the year ended December 31, 2011 (“Aetna’s Annual Report”), which was filed with the SEC on February 24, 2012, its proxy statement for its 2012 annual meeting of stockholders, which was filed with the SEC on April 9, 2012 and its Quarterly Report on Form 10-Q for the quarter ended June 30, 2012 (“Aetna’s Second Quarter 10-Q”) which was filed with the SEC on July 31, 2012. Other information regarding the participants in the proxy solicitations and a description of their direct and indirect interests, by security holdings or otherwise, are contained in the preliminary proxy statement/prospectus filed with the SEC and will be contained in the definitive proxy statement/prospectus and other relevant materials to be filed with the SEC when they become available.

Cautionary Statement Regarding Forward-Looking Statements

This communication may contain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. You can generally identify forward-looking statements by the use of forward-looking terminology such as “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “explore,” “evaluate,” “intend,” “may,” “might,” “plan,” “potential,” “predict,” “project,” “seek,” “should,” or “will,” or the negative thereof or other variations thereon or comparable terminology. These forward-looking statements are only predictions and involve known and unknown risks and uncertainties, many of which are beyond Aetna’s and Coventry’s control.

Statements in this document that are forward-looking, including projections as to the timing of the re-filing of Aetna’s premerger notification with the DOJ, the date of the Coventry special meeting of stockholders and the completion of the proposed transaction, are based on management’s estimates, assumptions and projections and are subject to significant uncertainties and other factors, many of which are beyond Aetna’s and Coventry’s control. Important risk factors could cause actual future events to differ materially from those currently expected by Coventry’s management, including but not limited to: the failure to receive on a timely basis or otherwise, the required approvals of Coventry’s stockholders and government or regulatory agencies; the risk that a condition to closing the proposed transaction may not be satisfied; and the outcome of various litigation matters related to the proposed transaction. For a further discussion of risks and uncertainties, please see the risk factors described in Coventry’s Annual Report on Form 10-K for the year ended December 31, 2011 (“Coventry Annual Report”), Coventry’s Quarterly Report for the quarter ending March 31, 2012 (“Coventry First Quarter 10-Q”), and Coventry’s Quarterly Report for the quarter ending June 30, 2012 (together with Coventry’s First Quarter 10-Q, “Coventry Quarterly Reports”), each on file with the SEC. You should also read the Coventry Annual Report and the Coventry Quarterly Reports for a discussion of Coventry’s historical results of operations and financial condition.

No assurances can be given that any of the events anticipated by the forward-looking statements will transpire or occur, or if any of them do occur, what impact they will have on the results of operations, financial condition or cash flows of Aetna or Coventry. Neither Aetna nor Coventry assumes any duty to update or revise forward-looking statements, whether as a result of new information, future events or otherwise, as of any future date.

Signature(s)

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.