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 9, 2012

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:

Item 1.01. Entry into a Material Definitive Agreement.

On November 9, 2012, Consumers Energy Company (“Consumers”), a principal subsidiary of CMS Energy Corporation, amended its Amended and Restated Receivables Purchase Agreement dated as of November 23, 2010 (the “Facility”). The parties to the Facility are listed in the Facility, which was previously filed as Exhibit 10.34 to the Form 10-K filed February 24, 2011 and is incorporated herein by reference. This amendment extends the term of the Facility until December 31, 2012.

JPMorgan Chase Bank, N.A. has provided banking and underwriting services to Consumers in the ordinary course of business.

The foregoing description of the amendment does not purport to be complete and is qualified in its entirety by the provisions of the amendment, which is attached hereto as Exhibit 10.1 and incorporated herein by reference.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits.

This Form 8-K contains “forward-looking statements” as defined in Rule 3b-6 of the Securities Exchange Act of 1934, as amended, Rule 175 of the Securities Act of 1933, as amended, and relevant legal decisions. The forward-looking statements are subject to risks and uncertainties. They should be read in conjunction with “FORWARD-LOOKING STATEMENTS AND INFORMATION” and “RISK FACTORS” sections of CMS Energy Corporation’s (“CMS Energy”) Form 10-K and Consumers Energy Company’s (“Consumers Energy”) Form 10-K each for the Year Ended December 31, 2011 and as updated in CMS Energy’s and Consumers Energy’s Forms 10-Q for the Quarters Ended March 31, 2012, June 30, 2012 and September 30, 2012. CMS Energy’s and Consumers Energy’s “FORWARD-LOOKING STATEMENTS AND INFORMATION” and “RISK FACTORS” sections are incorporated herein by reference and discuss important factors that could cause CMS Energy’s and Consumers Energy’s results to differ materially from those anticipated in such statements.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.

Exhibit Index