X0508 4 2024-02-28 0 0000075677 PACKAGING CORP OF AMERICA PKG 0001247456 KOWLZAN MARK W 1 N. FIELD COURT LAKE FOREST IL 60045 1 1 0 0 Chairman & CEO 0 Common Stock 2024-02-28 4 A 0 20098 0.00 A 515162 D Common Stock 2024-02-28 4 A 0 19711 0.00 A 534873 D Common Stock 2024-02-28 4 A 0 1913 0.00 A 536786 D Common Stock 2024-02-28 4 F 0 9580 176.36 D 527206 D Common Stock 18872 I 401k plan Common Stock 2565 I by spouse Award of restricted stock. On February 28, 2024, the Non-Employee Director subcommittee of the compensation committee of the registrant's board of directors certified attainment of the performance measure under the performance units awarded to reporting person on February 25, 2020. Performance was achieved at the 100% level. The units paid out on the date of certification. Payout in shares of accumulated dividends on vesting performance units. Pursuant to the terms of the Company's Long-Term Equity Incentive Plan, the Company withheld shares to cover the withholding tax obligation associated with equity awards vesting on the transaction date. Reporting person disclaims beneficial ownership of shares held by spouse. Kent A. Pflederer, attorney in fact 2024-03-01