UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF ☒ 1934 For quarterly period ended March 31, 2023 TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF ☐ 1934 For transition period from __________ to __________ Commission File Number: 001-15393 HEARTLAND FINANCIAL USA, INC. (Exact name of Registrant as specified in its charter) Delaware (State or other jurisdictio ...