UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) x Annual Report Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 for the Fiscal Year Ended December 31, 2023 o Transition Report Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Commission File Number 001-39029 MEDIACO HOLDING INC. (Exact name of registrant as specified in its charter) Indiana (State of incorporation or organization) 84-2427771 (I.R.S. Employer Identificat ...