PACKAGING CORP OF AMERICA 10-Q

Item 2. UNREGISTERED SALES OF EQUI TY SECURITIES AND USE OF PROCEEDS The following table presents information related to our repurchases of common stock made under repurchase plans authorized by PCA's Board of Directors, and shares withheld to cover taxes on vesting of equity awards, during the three months ended September 30, 2024: Issuer Purchases of Equity Securities Period Total Number of Shares Purchased (a) Average Price Paid Per Share Total Number of Shares Purchased as Part of Publicly Announced Plans or Programs Approximate Dollar Value of Shares That May Yet Be Purchased Under the Plans or Programs (in millions) July 1-31, 2024 2,883 $ 184.29 — $ 436.0 August 1-31, 2024 — — — 436.0 September 1-30, 2024 713 206.54 — 436.0 Total 3,596 $ 188.70 — $ 436.0 (a) All shares were withheld from employees to cover income and payroll taxes on equity awards that vested during the period. Item 3. DEFAULTS UPO N SENIOR SECURITIES None. Item 4. MINE SAF ETY DISCLOSURES Not applicable. Item 5. OTHE R INFORMATION During the three months ended September 30, 2024, none of the Company's directors or officers adopted or terminated any contract, instruction, or written plan for the purchase or sale of our securities intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act or any non-Rule 10b5-1 trading arrangements as defined in Item 408(a) of Regulation S-K. 28 Item 6. EXHIBITS Exhibit Number Description 31.1 Certification of Chief Executive Officer, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. † 31.2 Certification of Chief Financial Officer, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. † 32 Certification of Chief Executive Officer and Chief Financial Officer Pursuant to 18 U.S.C. §1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. † 101.INS Inline XBRL Instance Document – the instance document does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL document. † 101.SCH Inline XBRL Taxonomy Extension Schema Document. † 104 Cover Page Interactive Data File (formatted as inline XBRL and contained in Exhibit 101). † † Filed herewith. 29 SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized. Packaging Corporation of America /s/ ROBERT P. MUNDY Robert P. Mundy Executive Vice President and Chief Financial Officer Date: November 7, 2024 30