William Jefferson Jr. - 27 Feb 2026 Form 4 Insider Report for NISOURCE INC. (NI)

Role: EVP, Chief Op & Safety Officer
Signature: /s/ Ashley Bancroft, Attorney-in-Fact
Issuer symbol: NI
Transactions as of: 27 Feb 2026
Net transactions value: +$1,496,619
Form type: 4
Filing time: 03 Mar 2026, 16:58:19 UTC
Previous filing: 23 Jan 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Jefferson William Jr.	EVP, Chief Op & Safety Officer	801 E. 86TH AVENUE, MERRILLVILLE	/s/ Ashley Bancroft, Attorney-in-Fact	03 Mar 2026	0001935312

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	NI	Common Stock	Award	$2,867,468	+60,623	+91%	$47.30	127,357	27 Feb 2026	Direct	F1
transaction	NI	Common Stock	Tax liability	$1,206,339	-25,504	-20%	$47.30	101,853	27 Feb 2026	Direct	F2
transaction	NI	Common Stock	Tax liability	$164,509	-3,478	-3.4%	$47.30	98,375	27 Feb 2026	Direct	F3

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Vesting of non-derivative performance stock units granted in 2023, which are exempt from liability under Section 16(b) of the Securities Exchange Act pursuant to rule 16b-3(d).
F2	Number of shares reported represent shares withheld to satisfy tax withholding obligations in connection with the vesting of the performance stock units above.
F3	Number of shares reported represent shares withheld to satisfy tax withholding obligations in connection with the vesting of the 2023 Restricted Stock Unit award.