[Form 4] NorthWestern Energy Group, Inc. Insider Trading Activity

Rhea-AI Filing Summary

NorthWestern Energy Group VP Michael R. Cashell reported equity award activity involving company common stock. On a grant dated February 24, 2026, he acquired 1,329 shares through vesting of performance units under the company’s 2020 Executive Retirement-Retention Plan, valued using the $68.45 closing price from February 11, 2026.

In a related move, 31 shares were disposed of to satisfy tax withholding obligations rather than through an open-market sale. After these transactions, his directly held common stock position was 25,652 shares, which also reflects deferred shares and dividend reinvestment as described in the footnotes.

Insider Trade Summary

2 transactions reported

Mixed 2 txns

Insider Cashell Michael R

Role VP - Transmission

Type	Security	Shares	Price	Value
Grant/Award	Common Stock	1,329	$68.45	$91K
Tax Withholding	Common Stock	31	$0.00	--

Holdings After Transaction: Common Stock — 25,683 shares (Direct)

Footnotes (1)

1. Includes underlying deferred share units that are issuable subsequent to the reporting person's termination of service from the company. Shares acquired upon 12/31/25 vesting of performance units granted under the company's 2020 Executive Retirement-Retention Plan. Share price is the closing share price on 2/11/26, the date when the company's Board of Directors approved payout and vesting of the award. Includes deferred shares acquired from dividend reinvestment.

Form 4 Insider Transactions: What Each Field Means →

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
Estimated average burden
hours per response:			0.5

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^*

Cashell Michael R

(Last) (First) (Middle)

11 EAST PARK STREET

(Street)

BUTTE MT 59701

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
NorthWestern Energy Group, Inc. [ NWE ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	VP - Transmission

3. Date of Earliest Transaction (Month/Day/Year)
02/24/2026

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(1)	02/24/2026		A		1,329(2)	A	$68.45(3)	25,683(4)	D
Common Stock	02/24/2026		F		31	D	$0	25,652	D

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. Includes underlying deferred share units that are issuable subsequent to the reporting person's termination of service from the company.

2. Shares acquired upon 12/31/25 vesting of performance units granted under the company's 2020 Executive Retirement-Retention Plan.

3. Share price is the closing share price on 2/11/26, the date when the company's Board of Directors approved payout and vesting of the award.

4. Includes deferred shares acquired from dividend reinvestment.

Remarks:

	Emily L. Folsom, by power of attorney	02/25/2026
	** 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.