X0306 4 2022-09-30 0000357173 OLD SECOND BANCORP INC OSBC 0001673321 Pilmer Donald 37 S. RIVER ST. AURORA IL 60506 false true false false EVP Old Second Bancorp, Inc. Common Stock 2022-09-30 5 J 0 13 0 A 3834 I By 401-K Plan Old Second Bancorp, Inc. Common Stock 2022-09-30 5 J 0 1 0 A 174 I By Profit Sharing Plan Old Second Bancorp, Inc. Common Stock 1450 I Spouse's IRA Old Second Bancorp, Inc. Common Stock 72326 D Of this total, 13 shares were allocated during the third quarter pursuant to the Old Second Bancorp Inc Employee Savings Plan and Trust. Information herein was provided by the Plan Trustee as of 9-30-22. Of this total, 1 share was allocated during the third quarter pursuant to the Old Second Bancorp Inc Salary Savings Plan and Trust. Information herein was provided by the Plan Trustee as of 9-30-22. These shares are held in spouse's IRA for which Mr. Pilmer is listed as a beneficiary. Included in this total are 44,933 shares held in a brokerage account and 27,393 shares of Restricted Stock Units. /s/ Shirley Cantrell, Attorney-in-Fact 2022-09-30