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) May 8, 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 8.01. Other Events.

On May 8, 2012, Consumers Energy Company (“Consumers”) issued and sold $375,000,000 principal amount of its 2.85% First Mortgage Bonds due 2022 (the “Bonds”), pursuant to a registration statement on Form S-3 that Consumers filed with the Securities and Exchange Commission utilizing a “shelf” registration process (No. 333-174906-01) (the “Registration Statement”), a Preliminary Prospectus Supplement dated May 1, 2012 to Prospectus dated June 15, 2011, an Issuer Free Writing Prospectus that included the final terms of the transaction, a Final Prospectus Supplement dated May 1, 2012 to Prospectus dated June 15, 2011 and an underwriting agreement among Consumers and the underwriters named in that agreement with respect to the Bonds. Consumers intends to use the net proceeds from the offering and cash on hand to redeem all outstanding Consumers 5.375% First Mortgage Bonds due 2013 ($375,000,000 aggregate principal amount).

This Current Report on Form 8-K is being filed to file certain documents in connection with the offering as exhibits to the Registration Statement.

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 Quarter Ended March 31, 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