DTM

SEC source: 0001140361-26-003566 · form4.xml · nonDerivative · entry 2

Slater David · CIK 0001724472 · Director · Exec. Chair and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 190,996.57

SEC source: 0001140361-26-003566 · form4.xml · nonDerivative · entry 1

Slater David · CIK 0001724472 · Director · Exec. Chair and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 203,378.57

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · shares: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

F2 · price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F1 · balance_after: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

SEC source: 0001140361-26-003562 · form4.xml · derivative · entry 3

Cox Melissa · CIK 0001928974 · E.V.P., Chief Admin. Off.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common stock · 2,094 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

F3 · derivative.exercise_date: This restricted stock unit vested on February 1, 2026.

F3 · derivative.expiration_date: This restricted stock unit vested on February 1, 2026.

SEC source: 0001140361-26-003562 · form4.xml · nonDerivative · entry 2

Cox Melissa · CIK 0001928974 · E.V.P., Chief Admin. Off.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,353.83

SEC source: 0001140361-26-003562 · form4.xml · nonDerivative · entry 1

Cox Melissa · CIK 0001928974 · E.V.P., Chief Admin. Off.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 7,532.83

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · shares: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

F2 · price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F1 · balance_after: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

SEC source: 0001140361-26-003039 · form4.xml · derivative · entry 1

Cox Melissa · CIK 0001928974 · E.V.P., Chief Admin. Off.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,850

Underlying: Common stock · 2,850 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F2 · derivative.exercise_date: This restricted stock unit will vest on March 1, 2028, subject to the Reporting Person's continued service with the Issuer through the applicable vesting date and provides for associated dividend equivalents under the Issuer's long-term incentive plan.

F2 · derivative.expiration_date: This restricted stock unit will vest on March 1, 2028, subject to the Reporting Person's continued service with the Issuer through the applicable vesting date and provides for associated dividend equivalents under the Issuer's long-term incentive plan.

SEC source: 0001140361-25-030603 · form4.xml · nonDerivative · entry 1

Cox Melissa · CIK 0001928974 · E.V.P., Chief Admin. Off.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,171

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $104.42 to $104.52, inclusive. The reporting person undertakes to provide to DT Midstream, Inc., any security holder of DT Midstream, 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 ranges set forth in this footnote.

SEC source: 0001140361-25-029661 · form4.xml · nonDerivative · entry 1

Jewell Jeffrey A · CIK 0001722782 · Executive V.P., CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 64,380

SEC source: 0001140361-25-028663 · form4.xml · derivative · entry 2

Pickle Elaine M · CIK 0001869022 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,208.5 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F3 · derivative.exercise_date: This restricted stock unit vested 25% on August 2, 2023, 25% on August 2, 2024 and 50% on August 2, 2025, subject to the Reporting Person's continued service with the Issuer through the applicable vesting date.

F3 · derivative.expiration_date: This restricted stock unit vested 25% on August 2, 2023, 25% on August 2, 2024 and 50% on August 2, 2025, subject to the Reporting Person's continued service with the Issuer through the applicable vesting date.

SEC source: 0001140361-25-028663 · form4.xml · nonDerivative · entry 1

Pickle Elaine M · CIK 0001869022 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 4,308

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · shares: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

F2 · price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F1 · balance_after: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

SEC source: 0001140361-25-028658 · form4.xml · derivative · entry 3

Zona Christopher · CIK 0001869034 · E.V.P., Chief Oper. Off.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 18,125 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F3 · derivative.exercise_date: This restricted stock unit vested 25% on August 2, 2023, 25% on August 2, 2024 and 50% on August 2, 2025, subject to the Reporting Person's continued service with the Issuer through the applicable vesting date.

F3 · derivative.expiration_date: This restricted stock unit vested 25% on August 2, 2023, 25% on August 2, 2024 and 50% on August 2, 2025, subject to the Reporting Person's continued service with the Issuer through the applicable vesting date.

SEC source: 0001140361-25-028658 · form4.xml · nonDerivative · entry 2

Zona Christopher · CIK 0001869034 · E.V.P., Chief Oper. Off.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 71,149

SEC source: 0001140361-25-028658 · form4.xml · nonDerivative · entry 1

Zona Christopher · CIK 0001869034 · E.V.P., Chief Oper. Off.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 81,064

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · shares: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

F2 · price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F1 · balance_after: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

SEC source: 0001140361-25-028657 · form4.xml · derivative · entry 3

Ellis Wendy · CIK 0001864357 · E.V.P., Gen Counsel & Corp Sec

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 12,083.5 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F3 · derivative.exercise_date: This restricted stock unit vested 25% on August 2, 2023, 25% on August 2, 2024 and 50% on August 2, 2025, subject to the Reporting Person's continued service with the Issuer through the applicable vesting date.

F3 · derivative.expiration_date: This restricted stock unit vested 25% on August 2, 2023, 25% on August 2, 2024 and 50% on August 2, 2025, subject to the Reporting Person's continued service with the Issuer through the applicable vesting date.

SEC source: 0001140361-25-028657 · form4.xml · nonDerivative · entry 2

Ellis Wendy · CIK 0001864357 · E.V.P., Gen Counsel & Corp Sec

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 13,138

SEC source: 0001140361-25-028657 · form4.xml · nonDerivative · entry 1

Ellis Wendy · CIK 0001864357 · E.V.P., Gen Counsel & Corp Sec

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,866

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · shares: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

F2 · price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F1 · balance_after: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

SEC source: 0001140361-25-028665 · form4.xml · derivative · entry 2

Tumminello Peter I · CIK 0001491158 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,208.5 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F3 · derivative.exercise_date: This restricted stock unit vested 25% on August 2, 2023, 25% on August 2, 2024 and 50% on August 2, 2025, subject to the Reporting Person's continued service with the Issuer through the applicable vesting date.

F3 · derivative.expiration_date: This restricted stock unit vested 25% on August 2, 2023, 25% on August 2, 2024 and 50% on August 2, 2025, subject to the Reporting Person's continued service with the Issuer through the applicable vesting date.

SEC source: 0001140361-25-028665 · form4.xml · nonDerivative · entry 1

Tumminello Peter I · CIK 0001491158 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 13,388

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · shares: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

F2 · price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F1 · balance_after: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

SEC source: 0001140361-25-028660 · form4.xml · derivative · entry 2

Baker Stephen W · CIK 0001488318 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,208.5 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F3 · derivative.exercise_date: This restricted stock unit vested 25% on August 2, 2023, 25% on August 2, 2024 and 50% on August 2, 2025, subject to the Reporting Person's continued service with the Issuer through the applicable vesting date.

F3 · derivative.expiration_date: This restricted stock unit vested 25% on August 2, 2023, 25% on August 2, 2024 and 50% on August 2, 2025, subject to the Reporting Person's continued service with the Issuer through the applicable vesting date.

SEC source: 0001140361-25-028660 · form4.xml · nonDerivative · entry 1

Baker Stephen W · CIK 0001488318 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,808

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · shares: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

F2 · price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F1 · balance_after: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

SEC source: 0001140361-25-028659 · form4.xml · derivative · entry 2

Wilson Dwayne Andree · CIK 0001391996 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,208.5 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F3 · derivative.exercise_date: This restricted stock unit vested 25% on August 2, 2023, 25% on August 2, 2024 and 50% on August 2, 2025, subject to the Reporting Person's continued service with the Issuer through the applicable vesting date.

F3 · derivative.expiration_date: This restricted stock unit vested 25% on August 2, 2023, 25% on August 2, 2024 and 50% on August 2, 2025, subject to the Reporting Person's continued service with the Issuer through the applicable vesting date.

SEC source: 0001140361-25-028659 · form4.xml · nonDerivative · entry 1

Wilson Dwayne Andree · CIK 0001391996 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,808

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · shares: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

F2 · price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F1 · balance_after: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

SEC source: 0001140361-25-028662 · form4.xml · derivative · entry 3

Jewell Jeffrey A · CIK 0001722782 · Executive V.P., CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 24,166.5 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F3 · derivative.exercise_date: This restricted stock unit vested 25% on August 2, 2023, 25% on August 2, 2024 and 50% on August 2, 2025, subject to the Reporting Person's continued service with the Issuer through the applicable vesting date.

F3 · derivative.expiration_date: This restricted stock unit vested 25% on August 2, 2023, 25% on August 2, 2024 and 50% on August 2, 2025, subject to the Reporting Person's continued service with the Issuer through the applicable vesting date.

SEC source: 0001140361-25-028662 · form4.xml · nonDerivative · entry 2

Jewell Jeffrey A · CIK 0001722782 · Executive V.P., CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 64,230

SEC source: 0001140361-25-028662 · form4.xml · nonDerivative · entry 1

Jewell Jeffrey A · CIK 0001722782 · Executive V.P., CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 93,091

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · shares: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

F2 · price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F1 · balance_after: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

SEC source: 0001140361-25-028664 · form4.xml · derivative · entry 3

Slater David · CIK 0001724472 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 43,499.5 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F3 · derivative.exercise_date: This restricted stock unit vested 25% on August 2, 2023, 25% on August 2, 2024 and 50% on August 2, 2025, subject to the Reporting Person's continued service with the Issuer through the applicable vesting date.

F3 · derivative.expiration_date: This restricted stock unit vested 25% on August 2, 2023, 25% on August 2, 2024 and 50% on August 2, 2025, subject to the Reporting Person's continued service with the Issuer through the applicable vesting date.

SEC source: 0001140361-25-028664 · form4.xml · nonDerivative · entry 2

Slater David · CIK 0001724472 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 174,414

SEC source: 0001140361-25-028664 · form4.xml · nonDerivative · entry 1

Slater David · CIK 0001724472 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 198,312

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · shares: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

F2 · price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F1 · balance_after: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

SEC source: 0001140361-25-028661 · form4.xml · derivative · entry 3

Cox Melissa · CIK 0001928974 · E.V.P., Chief Admin. Off.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 2,251.932 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F3 · derivative.exercise_date: This restricted stock unit vested 25% on August 2, 2023, 25% on August 2, 2024 and 50% on August 2, 2025, subject to the Reporting Person's continued service with the Issuer through the applicable vesting date.

F3 · derivative.expiration_date: This restricted stock unit vested 25% on August 2, 2023, 25% on August 2, 2024 and 50% on August 2, 2025, subject to the Reporting Person's continued service with the Issuer through the applicable vesting date.

SEC source: 0001140361-25-028661 · form4.xml · nonDerivative · entry 2

Cox Melissa · CIK 0001928974 · E.V.P., Chief Admin. Off.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,926

SEC source: 0001140361-25-028661 · form4.xml · nonDerivative · entry 1

Cox Melissa · CIK 0001928974 · E.V.P., Chief Admin. Off.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 11,967

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · shares: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

F2 · price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F1 · balance_after: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

SEC source: 0000947871-25-000502 · ownership.xml · derivative · entry 2

Archon Angela N · CIK 0001669602 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 1,758 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F3 · derivative.exercise_date: This restricted stock unit vested on May 10, 2025.

F3 · derivative.expiration_date: This restricted stock unit vested on May 10, 2025.

SEC source: 0000947871-25-000502 · ownership.xml · nonDerivative · entry 1

Archon Angela N · CIK 0001669602 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 4,895

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · shares: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

F2 · price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F1 · balance_after: Includes shares of the Issuer's common stock acquired under the Issuer's dividend reinvestment plan.

SEC source: 0000947871-25-000479 · ownership.xml · nonDerivative · entry 1

Jewell Jeffrey A · CIK 0001722782 · Executive V.P., CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 64,230

SEC source: 0000947871-25-000467 · ownership.xml · derivative · entry 1

SKAGGS ROBERT C JR · CIK 0001059354 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,145

Underlying: Common Stock · 1,145 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F2 · derivative.exercise_date: This restricted stock unit will vest on May 6, 2026, subject to the Reporting Person's continued service with the Issuer through the vesting date.

F2 · derivative.expiration_date: This restricted stock unit will vest on May 6, 2026, subject to the Reporting Person's continued service with the Issuer through the vesting date.

SEC source: 0000947871-25-000466 · ownership.xml · derivative · entry 1

Pickle Elaine M · CIK 0001869022 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,145

Underlying: Common Stock · 1,145 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F2 · derivative.exercise_date: This restricted stock unit will vest on May 6, 2026, subject to the Reporting Person's continued service with the Issuer through the vesting date.

F2 · derivative.expiration_date: This restricted stock unit will vest on May 6, 2026, subject to the Reporting Person's continued service with the Issuer through the vesting date.

SEC source: 0000947871-25-000465 · ownership.xml · derivative · entry 1

Archon Angela N · CIK 0001669602 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,145

Underlying: Common Stock · 1,145 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F2 · derivative.exercise_date: This restricted stock unit will vest on May 6, 2026, subject to the Reporting Person's continued service with the Issuer through the vesting date.

F2 · derivative.expiration_date: This restricted stock unit will vest on May 6, 2026, subject to the Reporting Person's continued service with the Issuer through the vesting date.

SEC source: 0000947871-25-000468 · ownership.xml · derivative · entry 1

Tumminello Peter I · CIK 0001491158 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,145

Underlying: Common Stock · 1,145 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F2 · derivative.exercise_date: This restricted stock unit will vest on May 6, 2026, subject to the Reporting Person's continued service with the Issuer through the vesting date.

F2 · derivative.expiration_date: This restricted stock unit will vest on May 6, 2026, subject to the Reporting Person's continued service with the Issuer through the vesting date.

SEC source: 0000947871-25-000469 · ownership.xml · derivative · entry 1

Baker Stephen W · CIK 0001488318 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,145

Underlying: Common Stock · 1,145 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F2 · derivative.exercise_date: This restricted stock unit will vest on May 6, 2026, subject to the Reporting Person's continued service with the Issuer through the vesting date.

F2 · derivative.expiration_date: This restricted stock unit will vest on May 6, 2026, subject to the Reporting Person's continued service with the Issuer through the vesting date.

SEC source: 0000947871-25-000470 · ownership.xml · derivative · entry 1

Wilson Dwayne Andree · CIK 0001391996 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,145

Underlying: Common Stock · 1,145 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F2 · derivative.exercise_date: This restricted stock unit will vest on May 6, 2026, subject to the Reporting Person's continued service with the Issuer through the vesting date.

F2 · derivative.expiration_date: This restricted stock unit will vest on May 6, 2026, subject to the Reporting Person's continued service with the Issuer through the vesting date.

SEC source: 0000947871-25-000303 · ownership.xml · nonDerivative · entry 16

SKAGGS ROBERT C JR · CIK 0001059354 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 38,652.797

F3 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $86.92 to $86.93, inclusive. The reporting person undertakes to provide to DT Midstream, Inc., any security holder of DT Midstream, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in this footnote.

F1 · balance_after: Transactions were not previously reported due to an inadvertent omission. Share amounts set forth in Column 5 of Table I reflect the number of securities beneficially owned following the reported transaction.

SEC source: 0000947871-25-000278 · ownership.xml · nonDerivative · entry 2

Ellis Wendy · CIK 0001864357 · E.V.P., Gen Counsel & Corp Sec

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,435

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $93.01 to $93.71, inclusive. The reporting person undertakes to provide to DT Midstream, Inc., any security holder of DT Midstream, 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 ranges set forth in this footnote.

SEC source: 0000947871-25-000278 · ownership.xml · nonDerivative · entry 1

Ellis Wendy · CIK 0001864357 · E.V.P., Gen Counsel & Corp Sec

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 16,989

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $92.35 to $92.96, inclusive. The reporting person undertakes to provide to DT Midstream, Inc., any security holder of DT Midstream, 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 ranges set forth in this footnote.

SEC source: 0000947871-25-000252 · ownership.xml · nonDerivative · entry 1

Jewell Jeffrey A · CIK 0001722782 · Executive V.P., CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 64,165

SEC source: 0000947871-25-000233 · ownership.xml · derivative · entry 3

Zona Christopher · CIK 0001869034 · E.V.P., Chief Oper. Off.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,419

Underlying: Common Stock · 5,419 shares

Expires not disclosed

F2 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F3 · derivative.exercise_date: This restricted stock unit will vest on February 25, 2028, subject to the Reporting Person's continued employment with the Issuer through the applicable vesting date.

F3 · derivative.expiration_date: This restricted stock unit will vest on February 25, 2028, subject to the Reporting Person's continued employment with the Issuer through the applicable vesting date.

SEC source: 0000947871-25-000233 · ownership.xml · nonDerivative · entry 2

Zona Christopher · CIK 0001869034 · E.V.P., Chief Oper. Off.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 59,418

SEC source: 0000947871-25-000233 · ownership.xml · nonDerivative · entry 1

Zona Christopher · CIK 0001869034 · E.V.P., Chief Oper. Off.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 69,160

F1 · price: Represents shares of the Issuer's common stock earned in respect of performance stock units, as certified by the Organization and Compensation Committee of the board of directors of the Issuer on February 25, 2025 based on achievement of the applicable performance conditions over the applicable performance period.

SEC source: 0000947871-25-000237 · ownership.xml · derivative · entry 3

Ellis Wendy · CIK 0001864357 · E.V.P., Gen Counsel & Corp Sec

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 3,420

Underlying: Common Stock · 3,420 shares

Expires not disclosed

F2 · derivative.exercise_price: Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock with any fractional shares being paid in cash.

F3 · derivative.exercise_date: This restricted stock unit will vest on February 25, 2028, subject to the Reporting Person's continued employment with the Issuer through the applicable vesting date.

F3 · derivative.expiration_date: This restricted stock unit will vest on February 25, 2028, subject to the Reporting Person's continued employment with the Issuer through the applicable vesting date.

SEC source: 0000947871-25-000237 · ownership.xml · nonDerivative · entry 2

Ellis Wendy · CIK 0001864357 · E.V.P., Gen Counsel & Corp Sec

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 25,289

SEC source: 0000947871-25-000237 · ownership.xml · nonDerivative · entry 1

Ellis Wendy · CIK 0001864357 · E.V.P., Gen Counsel & Corp Sec

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 35,040

F1 · price: Represents shares of the Issuer's common stock earned in respect of performance stock units, as certified by the Organization and Compensation Committee of the board of directors of the Issuer on February 25, 2025 based on achievement of the applicable performance conditions over the applicable performance period.