X0306 4 2023-02-22 0 0000075677 PACKAGING CORP OF AMERICA PKG 0001318252 Hassfurther Thomas A 1 N. FIELD COURT LAKE FOREST IL 60045 0 1 0 0 Exec. VP Common Stock 2023-02-22 4 A 0 16454 0.00 A 209463 D Common Stock 2023-02-22 4 A 0 13352 0.00 A 222815 D Common Stock 11183 I by 401(k) plan Common Stock 53862 I By Spouse Common Stock 34293 I Through investment entity Award of restricted stock. On February 22, 2023, the Section 162(m) 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 June 28, 2019. Performance was achieved at the 100% level, which will result in the reported number of shares being paid out on June 28, 2023, the vesting date of the units, subject to continued service by the reporting person through such date. Reporting person disclaims beneficial ownership of shares held by spouse. Reporting person disclaims beneficial ownership of shares held by investment entity except to the extent of his pecuniary interest therein. Kent A. Pflederer, attorney in fact 2023-02-24