[Form 4] PACKAGING CORP OF AMERICA Insider Trading Activity

Rhea-AI Filing Summary

Mark W. Kowlzan, Chairman & CEO and Director of Packaging Corp of America (PKG), reported an insider sale. On 09/11/2025 he sold 25,000 shares of PKG common stock at a weighted average sale price of $215.97 per share. After the reported transaction he beneficially owned 437,378 shares directly. The filing also reports indirect holdings of 19,568 shares in a 401(k) plan and 2,565 shares held by his spouse, of which he disclaims beneficial ownership. The Form 4 was signed by an attorney-in-fact on 09/15/2025.

Positive

• None.

Negative

• Insider sale: Reporting person sold 25,000 shares of PKG common stock on 09/11/2025 at a weighted average price of $215.97.
• Spouse-held shares disclaimed: The filing notes 2,565 shares held by spouse, which the reporting person disclaims beneficial ownership of.

Insights

Corporate Governance Expert

TL;DR: A material insider sale was disclosed; holdings remain substantial, so governance concerns are limited but worth monitoring.

The Form 4 shows a single reported sale of 25,000 shares by Chairman & CEO Mark W. Kowlzan at a weighted average price of $215.97 on 09/11/2025. Post-transaction direct beneficial ownership stands at 437,378 shares, plus indirect holdings reported in a 401(k) plan and by a spouse. This disclosure is routine under Section 16 and provides transparency about insider liquidity. Because meaningful ownership remains, the sale alone does not indicate a change in control or governance but is a datapoint investors use to assess insider alignment.

Securities Analyst

TL;DR: Insider sold a modest block of shares; transaction is material for disclosure but not clearly indicative of company performance.

The filing documents a sale (code S) of 25,000 shares at a weighted average price of $215.97, reducing the reporting person to 437,378 directly held shares. The presence of additional indirect holdings (19,568 in a 401(k) and 2,565 held by spouse) is disclosed, with the spouse-held shares disclaimed. From a market-impact perspective, the disclosed sale is significant enough to require reporting but does not on its own provide information about company fundamentals or future expectations.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

KOWLZAN MARK W

(Last) (First) (Middle)

1 N. FIELD COURT

(Street)

LAKE FOREST IL 60045

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
PACKAGING CORP OF AMERICA [ PKG ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chairman & CEO

3. Date of Earliest Transaction (Month/Day/Year)
09/11/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	09/11/2025		S		25,000	D	$215.97(1)	437,378	D
Common Stock								19,568	I	401k plan
Common Stock								2,565	I	by spouse(2)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. 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.

2. Reporting person disclaims beneficial ownership of shares held by spouse.

	Kent A. Pflederer, attorney in fact	09/15/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did PKG CEO Mark W. Kowlzan report on Form 4?

He reported a sale of 25,000 shares of Packaging Corp of America common stock on 09/11/2025 at a weighted average price of $215.97.

How many PKG shares does Mark W. Kowlzan beneficially own after the sale?

The Form 4 reports he beneficially owns 437,378 shares directly following the transaction.

Are there any indirect holdings reported for Mark W. Kowlzan?

Yes. The filing discloses 19,568 shares held in a 401(k) plan (indirect) and 2,565 shares held by a spouse, which he disclaims beneficial ownership of.

When was the Form 4 signed and filed?

The signature on the Form 4 is dated 09/15/2025 and was executed by an attorney-in-fact, Kent A. Pflederer.

What transaction code was used for the sale?

The sale is coded as "S" on the Form 4, indicating a sale of shares.