X0306 4/A 2021-09-15 2021-09-21 0 0000715579 ACNB CORP ACNB 0001800429 Chaney Kimberly S 16 LINCOLN SQUARE GETTYSBURG PA 17325 1 0 0 0 ACNB Corporation Common 2021-09-15 2021-09-17 4 A 0 104.0536 27.63 A 6731.3533 D The date of execution was determined in accordance with SEC Rule 16a-3(g)(2) and (g)(4). The shares represent stock received in lieu of director fees pursuant to a plan. The amount of securities beneficially owned includes 6.171915 shares of common stock purchased for the same Transaction Date of September 15, 2021, through the automatic reinvestment of dividends under the ACNB Corporation Dividend Reinvestment and Stock Purchase Plan, which are exempt from the reporting requirements of Section 16 of the Securities Exchange Act of 1934. This Form 4/A amends the Form 4 filed earlier on September 21, 2021, to correct the Transaction Code from P to A. /s/ Lynda L. Glass as POA for Kimberly S. Chaney 2021-09-21