PACKAGING CORP OF AMERICA (PKG) · Insider Trading (Form 4) SEC Filing

=== SEC Form 4 — Statement of Changes in Beneficial Ownership === Document Type: 4 Period of Report: 2026-05-27 10b5-1 Pre-arranged Plan: No --- Issuer --- Name: PACKAGING CORP OF AMERICA (PKG) CIK: 0000075677 --- Reporting Owner --- Name: KOWLZAN MARK W CIK: 0001247456 Role: Director, Officer (Chairman & CEO) --- Non-Derivative Transactions --- [Transaction #1] Security: Common Stock Date: 2026-05-27 | Code: S (Open market sale) Shares: -9,266 | Price: $217.08 Total Value: $2,011,426.22 Shares Owned After: 473,610 | Ownership: D (Direct) Footnotes: [F1] The price listed is the weighted average sale price. The reporting person undertakes to provide full information regarding the number of shares sold at each separate price upon request. --- Holdings --- [Holding #1] Security: Common Stock Ownership: I (Indirect) [Holding #2] Security: Common Stock Ownership: I (Indirect) Footnotes: [F2] Reporting person disclaims beneficial ownership of shares held by spouse. --- Footnotes (Complete Index) --- F1: The price listed is the weighted average sale price. The reporting person undertakes to provide full information regarding the number of shares sold at each separate price upon request. F2: Reporting person disclaims beneficial ownership of shares held by spouse. --- Signature --- /s/ Kent A. Pflederer, attorney in fact (2026-05-28)