UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-K

For the fiscal year ended December 31, 2016

For the transition period from                 to                

Commission file number 00-24525

(Address, including zip code, and telephone number, including area code, of registrant’s principal offices)

Securities Registered Pursuant to Section 12(b) of the Act:

None

Securities Registered Pursuant to Section 12(g) of the Act:

Class A Common Stock, par value $.01 per share

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes   ¨     No   þ

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.    Yes   ¨     No   þ

Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes   þ     No   ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate website, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes   þ     No   ¨

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of Registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.     ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer”, “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act (Check one):

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes   ¨     No   þ

The aggregate market value of the registrant’s outstanding voting and non-voting common stock held by non-affiliates of the registrant (assuming, solely for the purposes hereof, that all officers and directors (and their respective affiliates), and 10% or greater stockholders of the registrant are affiliates of the registrant, some of whom may not be deemed to be affiliates upon judicial determination) as of June 30, 2016, the last business day of the registrant’s most recently completed second fiscal quarter, was approximately $38.0 million .

As of March 9, 2017 , the registrant had outstanding 29,306,374 shares of common stock consisting of (i)  29,225,765 shares of Class A common stock; and (ii)  80,609  shares of Class C common stock.

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the registrant’s definitive proxy statement relating to its 2017 annual meeting of stockholders (the “2017 Proxy Statement”), to be filed with the Securities and Exchange Commission, are incorporated by reference in Part III, Items 10 to 14 of this Annual Report on Form 10-K as indicated herein.

CUMULUS MEDIA INC.

ANNUAL REPORT ON FORM 10-K

For the Fiscal Year Ended December 31, 2016