DTM · DT Midstream, Inc.

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

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.

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.

This restricted stock unit vested on May 6, 2026.

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.

This restricted stock unit will vest on May 5, 2027, subject to the Reporting Person's continued service with the Issuer through the vesting date.

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.

This restricted stock unit will vest on May 5, 2027, subject to the Reporting Person's continued service with the Issuer through the vesting date.

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.

This restricted stock unit will vest on May 5, 2027, subject to the Reporting Person's continued service with the Issuer through the vesting date.

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.

This restricted stock unit will vest on May 5, 2027, subject to the Reporting Person's continued service with the Issuer through the vesting date.

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.

This restricted stock unit will vest on May 5, 2027, subject to the Reporting Person's continued service with the Issuer through the vesting date.

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.

This restricted stock unit will vest on May 5, 2027, subject to the Reporting Person's continued service with the Issuer through the vesting date.

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

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.

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.

This restricted stock unit vested 55.56% on May 4, 2023, and the remaining 44.44% vested on May 4, 2026.

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

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.

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.

Restricted stock units of which 965 vested on March 5, 2026 and 965 vest on March 5, 2027, together with associated dividend equivalents, subject to the Reporting Person's continued employment with the Issuer through the applicable vesting dates.

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.

This restricted stock unit will vest on February 20, 2029, 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.

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.

This restricted stock unit will vest on February 20, 2029, 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.

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.

This restricted stock unit will vest on February 20, 2029, 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.

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.

This restricted stock unit will vest on February 20, 2029, 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.

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.

This restricted stock unit will vest on February 20, 2029, 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.

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.

This restricted stock unit will vest on February 20, 2029, 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.

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 17, 2026 based on achievement of the applicable performance conditions over the applicable performance period.

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 17, 2026 based on achievement of the applicable performance conditions over the applicable performance period.

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 17, 2026 based on achievement of the applicable performance conditions over the applicable performance period.

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 17, 2026 based on achievement of the applicable performance conditions over the applicable performance period.

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 17, 2026 based on achievement of the applicable performance conditions over the applicable performance period.

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 17, 2026 based on achievement of the applicable performance conditions over the applicable performance period.

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

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.

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

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.

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.

This restricted stock unit vested on February 1, 2026.

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

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.

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.

This restricted stock unit vested on February 1, 2026.

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

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.

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

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.

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.

This restricted stock unit vested on February 1, 2026.

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.

This restricted stock unit vested February 1, 2026.

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

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.

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.

This restricted stock unit vested on February 1, 2026.