X0306 4 2017-02-28 0 0000075677 PACKAGING CORP OF AMERICA PKG 0001247456 KOWLZAN MARK W 1955 WEST FIELD COURT LAKE FOREST IL 60045 1 1 0 0 Chairman & CEO Common Stock 2017-02-28 4 A 0 26000 0.00 A 325718 D Common Stock 13315 I by 401(k) plan Common Stock 1605 I By Spouse On February 28, 2017, 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 24, 2013. Performance was achieved at the 100% level, which will result in the reported number of shares being paid out on June 24, 2017, the vesting date of the units, subject to continued service by the reporting person through such date. The committee has the discretion to award up to an additional 20% of the number of units on or around the vesting date. Reporting person disclaims beneficial ownership of such shares. Kent A. Pflederer, attorney in fact 2017-03-01