NI · Nisource Inc. · Insider Trading

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $42.39 to $42.42, inclusive. The reporting person undertakes to provide to NiSource Inc., any security holder of NiSource Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

Transfer of shares from indirectly held to directly held, which transfer is exempt from Section 16 reporting under Rule 16a-13.

This amount includes RSUs received pursuant to the dividend equivalent provisions of the RSU awards, and which are subject to the same vesting conditions as the underlying RSUs.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $47.670 to $47.713, inclusive. The reporting person undertakes to provide to NiSource Inc., any security holder of NiSource Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $47.730 to $47.745, inclusive. The reporting person undertakes to provide to NiSource Inc., any security holder of NiSource Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

This amount includes RSUs received pursuant to the dividend equivalent provisions of his director RSU awards from 2020 and 2021, and which are subject to the same vesting conditions as the underlying RSUs.

Includes shares acquired through the NiSource Inc. Employee Stock Purchase Plan.

Includes shares acquired through dividend reinvestments.

Late due to administrative error.

Represents an award of restricted stock units ("RSU") granted as part of the non-employee director's annual compensation and which vests in full on the first anniversary of the grant date, subject to certain acceleration conditions. RSUs represent a contingent right to receive one share of the Company's common stock upon vesting pursuant to the Company's 2020 Omnibus Plan.

This amount includes RSUs received pursuant to the dividend equivalent provisions of the RSU awards, and which are subject to the same vesting conditions as the underlying RSUs.

Represents an award of restricted stock units ("RSU") granted as part of the non-employee director's annual compensation and which vests in full on the first anniversary of the grant date, subject to certain acceleration conditions.RSUs represent a contingent right to receive one share of the Company's common stock upon vesting pursuant to the Company's 2020 Omnibus Plan.

This amount includes RSUs received pursuant to the dividend equivalent provisions of the RSU awards, and which are subject to the same vesting conditions as the underlying RSUs.

Represents an award of restricted stock units ("RSU") granted as part of the non-employee director's annual compensation and which vests in full on the first anniversary of the grant date, subject to certain acceleration conditions. RSUs represent a contingent right to receive one share of the Company's common stock upon vesting pursuant to the Company's 2020 Omnibus Plan.

This amount includes RSUs received pursuant to the dividend equivalent provisions of the RSU awards, and which are subject to the same vesting conditions as the underlying RSUs.

Represents an award of restricted stock units ("RSU") granted as part of the non-employee director's annual compensation and which vests in full on the first anniversary of the grant date, subject to certain acceleration conditions. RSUs represent a contingent right to receive one share of the Company's common stock upon vesting pursuant to the Company's 2020 Omnibus Plan.

This amount includes RSUs received pursuant to the dividend equivalent provisions of the RSU awards, and which are subject to the same vesting conditions as the underlying RSUs.

Represents an award of restricted stock units ("RSU") granted as part of the non-employee director's annual compensation and which vests in full on the first anniversary of the grant date, subject to certain acceleration conditions. RSUs represent a contingent right to receive one share of the Company's common stock upon vesting pursuant to the Company's 2020 Omnibus Plan.

This amount includes RSUs received pursuant to the dividend equivalent provisions of the RSU awards, and which are subject to the same vesting conditions as the underlying RSUs.

Represents an award of restricted stock units ("RSU") granted as part of the non-employee director's annual compensation and which vests in full on the first anniversary of the grant date, subject to certain acceleration conditions. RSUs represent a contingent right to receive one share of the Company's common stock upon vesting pursuant to the Company's 2020 Omnibus Plan.

This amount includes RSUs received pursuant to the dividend equivalent provisions of the RSU awards, and which are subject to the same vesting conditions as the underlying RSUs.

Represents an award of restricted stock units ("RSU") granted as part of the non-employee director's annual compensation and which vests in full on the first anniversary of the grant date, subject to certain acceleration conditions. RSUs represent a contingent right to receive one share of the Company's common stock upon vesting pursuant to the Company's 2020 Omnibus Plan.

This amount includes RSUs received pursuant to the dividend equivalent provisions of the RSU awards, and which are subject to the same vesting conditions as the underlying RSUs.

Represents an award of restricted stock units ("RSU") granted as part of the non-employee director's annual compensation and which vests in full on the first anniversary of the grant date, subject to certain acceleration conditions. RSUs represent a contingent right to receive one share of the Company's common stock upon vesting pursuant to the Company's 2020 Omnibus Plan.

This amount includes RSUs received pursuant to the dividend equivalent provisions of the RSU awards, and which are subject to the same vesting conditions as the underlying RSUs.

Represents an award of restricted stock units ("RSU") granted as part of the non-employee director's annual compensation and which vests in full on the first anniversary of the grant date, subject to certain acceleration conditions. RSUs represent a contingent right to receive one share of the Company's common stock upon vesting pursuant to the Company's 2020 Omnibus Plan.

This amount includes RSUs received pursuant to the dividend equivalent provisions of the RSU awards, and which are subject to the same vesting conditions as the underlying RSUs.

Represents an award of restricted stock units ("RSU") granted as part of the non-employee director's annual compensation and which vests in full on the first anniversary of the grant date, subject to certain acceleration conditions. RSUs represent a contingent right to receive one share of the Company's common stock upon vesting pursuant to the Company's 2020 Omnibus Plan.

This amount includes RSUs received pursuant to the dividend equivalent provisions of the RSU awards, and which are subject to the same vesting conditions as the underlying RSUs.

Represents an award of restricted stock units ("RSU") granted as part of the non-employee director's annual compensation and which vests in full on the first anniversary of the grant date, subject to certain acceleration conditions. RSUs represent a contingent right to receive one share of the Company's common stock upon vesting pursuant to the Company's 2020 Omnibus Plan.

This amount includes RSUs received pursuant to the dividend equivalent provisions of the RSU awards, and which are subject to the same vesting conditions as the underlying RSUs.

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).

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).

Number of shares reported represent shares withheld to satisfy tax withholding obligations in connection with the vestings of the 2023 Restricted Stock Unit awards.

Includes shares acquired through dividend reinvestments.

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).

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).

Number of shares reported represent shares withheld to satisfy tax withholding obligations in connection with the vesting of the 2023 Restricted Stock Unit award.

Includes shares acquired through dividend reinvestments.

Number of shares reported represent shares withheld to satisfy tax withholding obligations in connection with the vesting of the performance stock units above.

Number of shares reported represent shares withheld to satisfy tax withholding obligations in connection with the vesting of the performance stock units above.

Number of shares reported represent shares withheld to satisfy tax withholding obligations in connection with the vesting of the performance stock units above.

Number of shares reported represent shares withheld to satisfy tax withholding obligations in connection with the vesting of the performance stock units above.

Number of shares reported represent shares withheld to satisfy tax withholding obligations in connection with the vesting of the special performance stock units above.

Number of shares reported represent shares withheld to satisfy tax withholding obligations in connection with the vesting of the 2023 Restricted Stock Unit award.

Vesting of non-derivative special 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).

Number of shares reported represent shares withheld to satisfy tax withholding obligations in connection with the vesting of the performance stock units above.

Number of shares reported represent shares withheld to satisfy tax withholding obligations in connection with the vesting of the performance stock units above.

Number of shares reported represent shares withheld to satisfy tax withholding obligations in connection with the vesting of the performance stock units above.

Number of shares reported represent shares withheld to satisfy tax withholding obligations in connection with the vesting of the 2023 Restricted Stock Unit award.

Includes shares acquired through the NiSource Inc. Employee Stock Purchase Plan.

Number of shares reported represent shares withheld to satisfy tax withholding obligations in connection with the vesting of the 2023 Restricted Stock Unit award.

This amount includes RSUs received pursuant to the dividend equivalent provisions of his director RSU awards from 2020 and 2021, and which are subject to the same vesting conditions as the underlying RSUs.

Includes shares acquired through the NiSource Inc. Employee Stock Purchase Plan.

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).

Number of shares reported represent shares withheld to satisfy tax withholding obligations in connection with the vesting of the 2023 Restricted Stock Unit award.

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).

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).

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).

Number of shares reported represent shares withheld to satisfy tax withholding obligations in connection with the vesting of the 2023 Restricted Stock Unit award.

Number of shares reported represent shares withheld to satisfy tax withholding obligations in connection with the vesting of the 2023 Restricted Stock Unit award.

Number of shares reported represent shares withheld to satisfy tax withholding obligations in connection with the vesting of the performance stock units above.

The reported sale of 12,500 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on November 10, 2025.

Includes shares acquired through dividend reinvestments.

Number of shares reported represent shares withheld to satisfy tax withholding obligations in connection with the partial vesting of the 2024 Special Restricted Stock Unit award.

Includes shares acquired through dividend reinvestments.

Each Restricted Stock Unit ("RSU") represents a contingent right to receive one share of the Company's common stock pursuant to the NiSource Inc. 2020 Omnibus Incentive Plan. Subject to certain forfeiture conditions, the RSUs will 100% vest on February 28, 2029, provided that the reporting person is continuously employed by the Company through and including that date.

Includes shares acquired through the NiSource Inc. Employee Stock Purchase Plan.

This amount includes RSUs received pursuant to the dividend equivalent provisions of his director RSU awards from 2020 and 2021, and which are subject to the same vesting conditions as the underlying RSUs.

Number of shares reported represent shares withheld to satisfy tax withholding obligations in connection with the partial vesting of the 2025 Special Restricted Stock Unit award.

Includes shares acquired through the NiSource Inc. Employee Stock Purchase Plan.

Each Restricted Stock Unit ("RSU") represents a contingent right to receive one share of the Company's common stock pursuant to the NiSource Inc. 2020 Omnibus Incentive Plan. Subject to certain forfeiture conditions, the RSUs will 100% vest on February 28, 2029, provided that the reporting person is continuously employed by the Company through and including that date.

Each Restricted Stock Unit ("RSU") represents a contingent right to receive one share of the Company's common stock pursuant to the NiSource Inc. 2020 Omnibus Incentive Plan. Subject to certain forfeiture conditions, the RSUs will 100% vest on February 28, 2029, provided that the reporting person is continuously employed by the Company through and including that date.