X0306 4 2018-12-31 0 0000357173 OLD SECOND BANCORP INC OSBC 0001673321 Pilmer Donald 37 S. RIVER ST. AURORA IL 60506 0 1 0 0 EVP Old Second Bancorp, Inc. Common Stock 2018-12-31 4 A 0 49 A 2876 I 401k Plan Old Second Bancorp, Inc. Common Stock 926 I Profit Sharing Plan Old Second Bancorp, Inc. Common Stock 46408.054 D Old Second Bancorp, Inc. Common Stock 1450 I Spouse's IRA These shares are held in spouse's IRA for which Mr. Pilmer is listed as a beneficiary. Included in this total are 22,806 shares held in brokerage; 23,566 shares of Restricted Stock Units and 36.054 shares of Restricted Stock Equivalents. Of this total, 49 shares were allocated during the fourth quarter pursuant to the Old Second Bancorp, Inc. Profit Sharing Plan. Information herein was provided by the Plan Trustee as of 12-31-18. Does not apply. /s/ Donald Pilmer 2018-12-31