SMC · Summit Midstream Corp

These Common Stocks were sold in compliance with a qualified selling plan adopted by the reporting person pursuant to Rule 10b5-1 under the Securities Exchange Act of 1934, as amended.

The price reported in Column 4 is a weighted average price and has been rounded to the nearest cent. These Common Stocks were sold in multiple transactions at prices ranging from $29.42 to $30.13, inclusive. The reporting person undertakes to provide to Summit Midstream Corporation, any security holder of Summit Midstream Corporation, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of Common Stocks sold at each separate price within the ranges set forth in footnote 2 to this Form 4.

The Reporting Person is a trustee of the Joint Spousal Trust. The Reporting Person and his spouse are the sole beneficiaries of the Joint Spousal Trust.

The Reporting Person is a trustee of the Joint Spousal Trust. The Reporting Person and his spouse are the sole beneficiaries of the Joint Spousal Trust.

The reported securities are held directly by Connect Midstream, LLC. Tailwater Energy Fund III LP is the sole member of Connect Midstream, LLC. TW GP EF-III LP is the general partner of Tailwater Energy Fund III LP. TW GP EF-III GP, LLC is the general partner of TW GP EF-III LP. Tailwater Capital LLC is the sole member of TW GP EF-III GP, LLC. Jason Downie and Edward Herring are each a Managing Partner of Tailwater Capital LLC. Each of the foregoing disclaim beneficial ownership of the reported securities directly held by Connect Midstream, LLC except to the extent of their respective pecuniary interest therein.

Each corporation restricted stock unit is the economic equivalent of one common stock.

One-third of the corporation restricted stock units (rounded down to the nearest whole number of units, except in the case of the final vesting date) shall vest on each of the first, second and third anniversaries of the March 16, 2026, reference date, subject to continued employment and accelerated vesting as provided in the applicable award agreement. The Reporting Person will receive DERs for each corporation restricted stock unit, providing for payment on the vesting date of a lump sum of cash equal to the accrued distributions from and after the grant date of the corporation restricted stock units.

The corporation restricted stock units and associated DERs do not expire. The corporation restricted stock units are settled upon vesting in common stocks (on a one-for-one basis) or in cash, at the discretion of the Issuer.

Each corporation restricted stock unit is the economic equivalent of one common stock.

The corporation restricted stock units shall vest if and to the extent that the corporation restricted stock units are earned during the performance period from January 1, 2026 through December 31, 2028, which will depend on whether the performance criteria are achieved as determined by the committee as soon as reasonably practicable, but no later than sixty (60) days following December 31, 2028, the last day of the Performance Period. The vesting of the corporation restricted stock units is subject to continued employment and accelerated vesting as provided in the applicable award agreement. The Reporting Person will receive DERs for each corporation restricted stock unit, providing for payment on the vesting date of a lump sum of cash equal to the accrued distributions from and after the grant date of the corporation restricted stock units.

The corporation restricted stock units and associated DERs do not expire. The corporation restricted stock units are settled upon vesting in common stocks (on a one-for-one basis) or in cash, at the discretion of the Issuer.

This total includes corporation restricted stock units from other tranches with different vesting dates. On March 16, 2026, when the original award agreement vested, it was certified at an achievement level of 96.7% of the target number of corporation restricted stock units. The remaining 3.3% of the target corporation restricted stock units that were not earned based on the certified performance level were forfeited. The difference between the number of outstanding awards reflected in the Reporting Person's brokerage account and the number previously reported is attributable to this certification and the corresponding forfeiture of the unearned portion of the original award.

Each corporation restricted stock unit is the economic equivalent of one common stock.

One-third of the corporation restricted stock units (rounded down to the nearest whole number of units, except in the case of the final vesting date) shall vest on each of the first, second and third anniversaries of the March 16, 2026, reference date, subject to continued employment and accelerated vesting as provided in the applicable award agreement. The Reporting Person will receive DERs for each corporation restricted stock unit, providing for payment on the vesting date of a lump sum of cash equal to the accrued distributions from and after the grant date of the corporation restricted stock units.

The corporation restricted stock units and associated DERs do not expire. The corporation restricted stock units are settled upon vesting in common stocks (on a one-for-one basis) or in cash, at the discretion of the Issuer.

Each corporation restricted stock unit is the economic equivalent of one common stock.

The corporation restricted stock units shall vest if and to the extent that the corporation restricted stock units are earned during the performance period from January 1, 2026 through December 31, 2028, which will depend on whether the performance criteria are achieved as determined by the committee as soon as reasonably practicable, but no later than sixty (60) days following December 31, 2028, the last day of the Performance Period. The vesting of the corporation restricted stock units is subject to continued employment and accelerated vesting as provided in the applicable award agreement. The Reporting Person will receive DERs for each corporation restricted stock unit, providing for payment on the vesting date of a lump sum of cash equal to the accrued distributions from and after the grant date of the corporation restricted stock units.

The corporation restricted stock units and associated DERs do not expire. The corporation restricted stock units are settled upon vesting in common stocks (on a one-for-one basis) or in cash, at the discretion of the Issuer.

This total includes corporation restricted stock units from other tranches with different vesting dates. On March 16, 2026, when the original award agreement vested, it was certified at an achievement level of 96.7% of the target number of corporation restricted stock units. The remaining 3.3% of the target corporation restricted stock units that were not earned based on the certified performance level were forfeited. The difference between the number of outstanding awards reflected in the Reporting Person's brokerage account and the number previously reported is attributable to this certification and the corresponding forfeiture of the unearned portion of the original award.

Each corporation restricted stock unit is the economic equivalent of one common stock.

One-third of the corporation restricted stock units (rounded down to the nearest whole number of units, except in the case of the final vesting date) shall vest on each of the first, second and third anniversaries of the March 16, 2026, reference date, subject to continued employment and accelerated vesting as provided in the applicable award agreement. The Reporting Person will receive DERs for each corporation restricted stock unit, providing for payment on the vesting date of a lump sum of cash equal to the accrued distributions from and after the grant date of the corporation restricted stock units.

The corporation restricted stock units and associated DERs do not expire. The corporation restricted stock units are settled upon vesting in common stocks (on a one-for-one basis) or in cash, at the discretion of the Issuer.

Each corporation restricted stock unit is the economic equivalent of one common stock.

The corporation restricted stock units shall vest if and to the extent that the corporation restricted stock units are earned during the performance period from January 1, 2026 through December 31, 2028, which will depend on whether the performance criteria are achieved as determined by the committee as soon as reasonably practicable, but no later than sixty (60) days following December 31, 2028, the last day of the Performance Period. The vesting of the corporation restricted stock units is subject to continued employment and accelerated vesting as provided in the applicable award agreement. The Reporting Person will receive DERs for each corporation restricted stock unit, providing for payment on the vesting date of a lump sum of cash equal to the accrued distributions from and after the grant date of the corporation restricted stock units.

The corporation restricted stock units and associated DERs do not expire. The corporation restricted stock units are settled upon vesting in common stocks (on a one-for-one basis) or in cash, at the discretion of the Issuer.

This total includes corporation restricted stock units from other tranches with different vesting dates. On March 16, 2026, when the original award agreement vested, it was certified at an achievement level of 96.7% of the target number of corporation restricted stock units. The remaining 3.3% of the target corporation restricted stock units that were not earned based on the certified performance level were forfeited. The difference between the number of outstanding awards reflected in the Reporting Person's brokerage account and the number previously reported is attributable to this certification and the corresponding forfeiture of the unearned portion of the original award.

Each corporation restricted stock unit is the economic equivalent of one common stock.

The corporation restricted stock units shall vest if and to the extent that the corporation restricted stock units are earned during the performance period from January 1, 2026 through December 31, 2028, which will depend on whether the performance criteria are achieved as determined by the committee as soon as reasonably practicable, but no later than sixty (60) days following December 31, 2028, the last day of the Performance Period. The vesting of the corporation restricted stock units is subject to continued employment and accelerated vesting as provided in the applicable award agreement. The Reporting Person will receive DERs for each corporation restricted stock unit, providing for payment on the vesting date of a lump sum of cash equal to the accrued distributions from and after the grant date of the corporation restricted stock units.

The corporation restricted stock units and associated DERs do not expire. The corporation restricted stock units are settled upon vesting in common stocks (on a one-for-one basis) or in cash, at the discretion of the Issuer.

This total includes corporation restricted stock units from other tranches with different vesting dates. On March 16, 2026, when the original award agreement vested, it was certified at an achievement level of 96.7% of the target number of corporation restricted stock units. The remaining 3.3% of the target corporation restricted stock units that were not earned based on the certified performance level were forfeited. The difference between the number of outstanding awards reflected in the Reporting Person's brokerage account and the number previously reported is attributable to this certification and the corresponding forfeiture of the unearned portion of the original award.

Each corporation restricted stock unit is the economic equivalent of one common stock.

One-third of the corporation restricted stock units (rounded down to the nearest whole number of units, except in the case of the final vesting date) shall vest on each of the first, second and third anniversaries of the March 16, 2026, reference date, subject to continued employment and accelerated vesting as provided in the applicable award agreement. The Reporting Person will receive DERs for each corporation restricted stock unit, providing for payment on the vesting date of a lump sum of cash equal to the accrued distributions from and after the grant date of the corporation restricted stock units.

The corporation restricted stock units and associated DERs do not expire. The corporation restricted stock units are settled upon vesting in common stocks (on a one-for-one basis) or in cash, at the discretion of the Issuer.

Common stocks being withheld to pay tax liability.

Each corporation restricted stock unit is the economic equivalent of one common stock.

Each corporation restricted stock unit is the economic equivalent of one common stock.

Each corporation restricted stock unit is the economic equivalent of one common stock.

The corporation restricted stock units subject to the original award agreement vested on March 13, 2026. The Reporting Person received distribution equivalent rights ("DERs") for each corporation restricted stock unit, providing for payment on the vesting date of a lump sum of cash equal to the accrued distributions from and after the grant date of the corporation restricted stock units.

The corporation restricted stock units and associated DERs do not expire. The corporation restricted stock units are settled upon vesting in common stocks (on a one-for-one basis) or in cash, at the discretion of the Issuer.

Each corporation restricted stock unit is the economic equivalent of one common stock.

The final one-third of the corporation restricted stock units subject to the original award agreement vested on March 13, 2026. The Reporting Person received DERs for each corporation restricted stock unit, providing for payment on the vesting date of a lump sum of cash equal to the accrued distributions from and after the grant date of the corporation restricted stock units.

The corporation restricted stock units and associated DERs do not expire. The corporation restricted stock units are settled upon vesting in common stocks (on a one-for-one basis) or in cash, at the discretion of the Issuer.

Each corporation restricted stock unit is the economic equivalent of one common stock.

Each corporation restricted stock unit is the economic equivalent of one common stock.

Common stocks being withheld to pay tax liability.

Each corporation restricted stock unit is the economic equivalent of one common stock.

Each corporation restricted stock unit is the economic equivalent of one common stock.

Each corporation restricted stock unit is the economic equivalent of one common stock.

The final one-third of the corporation restricted stock units subject to the original award agreement vested on March 13, 2026. The Reporting Person received DERs for each corporation restricted stock unit, providing for payment on the vesting date of a lump sum of cash equal to the accrued distributions from and after the grant date of the corporation restricted stock units.

The corporation restricted stock units and associated DERs do not expire. The corporation restricted stock units are settled upon vesting in common stocks (on a one-for-one basis) or in cash, at the discretion of the Issuer.

Each corporation restricted stock unit is the economic equivalent of one common stock.

The final one-third of the corporation restricted stock units subject to the original award agreement vested on March 13, 2026. The Reporting Person received DERs for each corporation restricted stock unit, providing for payment on the vesting date of a lump sum of cash equal to the accrued distributions from and after the grant date of the corporation restricted stock units.

The corporation restricted stock units and associated DERs do not expire. The corporation restricted stock units are settled upon vesting in common stocks (on a one-for-one basis) or in cash, at the discretion of the Issuer.

Each corporation restricted stock unit is the economic equivalent of one common stock.

Each corporation restricted stock unit is the economic equivalent of one common stock.

Each corporation restricted stock unit is the economic equivalent of one common stock.

One-third of the corporation restricted stock units (rounded down to the nearest whole number of units, except in the case of the final vesting date) vested on March 13, 2026, with the remaining corporation restricted stock units vesting on the second and third anniversaries of the March 14, 2025, reference date, subject to continued employment and accelerated vesting as provided in the applicable award agreement. The Reporting Person received DERs for each corporation restricted stock unit, providing for payment on the vesting date of a lump sum of cash equal to the accrued distributions from and after the grant date of the corporation restricted stock units.

The corporation restricted stock units and associated DERs do not expire. The corporation restricted stock units are settled upon vesting in common stocks (on a one-for-one basis) or in cash, at the discretion of the Issuer.

Each corporation restricted stock unit is the economic equivalent of one common stock.

Each corporation restricted stock unit is the economic equivalent of one common stock.

Each corporation restricted stock unit is the economic equivalent of one common stock.

One-third of the corporation restricted stock units (rounded down to the nearest whole number of units, except in the case of the final vesting date) vested on March 13, 2026, with the remaining corporation restricted stock units vesting on the second and third anniversaries of the March 14, 2025, reference date, subject to continued employment and accelerated vesting as provided in the applicable award agreement. The Reporting Person received DERs for each corporation restricted stock unit, providing for payment on the vesting date of a lump sum of cash equal to the accrued distributions from and after the grant date of the corporation restricted stock units.

The corporation restricted stock units and associated DERs do not expire. The corporation restricted stock units are settled upon vesting in common stocks (on a one-for-one basis) or in cash, at the discretion of the Issuer.

Common stocks being withheld to pay tax liability.

Common stocks being withheld to pay tax liability.

Common stocks being withheld to pay tax liability.

Common stocks being withheld to pay tax liability.

Each corporation restricted stock unit is the economic equivalent of one common stock.

Each corporation restricted stock unit is the economic equivalent of one common stock.

One-third of the corporation restricted stock units (rounded down to the nearest whole number of units, except in the case of the final vesting date) vested on March 13, 2026, with the remaining corporation restricted stock units vesting on the second and third anniversaries of the March 14, 2025, reference date, subject to continued employment and accelerated vesting as provided in the applicable award agreement. The Reporting Person received DERs for each corporation restricted stock unit, providing for payment on the vesting date of a lump sum of cash equal to the accrued distributions from and after the grant date of the corporation restricted stock units.

The corporation restricted stock units and associated DERs do not expire. The corporation restricted stock units are settled upon vesting in common stocks (on a one-for-one basis) or in cash, at the discretion of the Issuer.

Each corporation restricted stock unit is the economic equivalent of one common stock.

The corporation restricted stock units subject to the original award agreement vested on March 13, 2026. The Reporting Person received distribution equivalent rights ("DERs") for each corporation restricted stock unit, providing for payment on the vesting date of a lump sum of cash equal to the accrued distributions from and after the grant date of the corporation restricted stock units.

The corporation restricted stock units and associated DERs do not expire. The corporation restricted stock units are settled upon vesting in common stocks (on a one-for-one basis) or in cash, at the discretion of the Issuer.

Each corporation restricted stock unit is the economic equivalent of one common stock.

The final one-third of the corporation restricted stock units subject to the original award agreement vested on March 13, 2026. The Reporting Person received DERs for each corporation restricted stock unit, providing for payment on the vesting date of a lump sum of cash equal to the accrued distributions from and after the grant date of the corporation restricted stock units.

The corporation restricted stock units and associated DERs do not expire. The corporation restricted stock units are settled upon vesting in common stocks (on a one-for-one basis) or in cash, at the discretion of the Issuer.

Common stocks being withheld to pay tax liability.

Each corporation restricted stock unit is the economic equivalent of one common stock.

One-third of the corporation restricted stock units (rounded down to the nearest whole number of units, except in the case of the final vesting date) vested on March 13, 2026, with the remaining corporation restricted stock units vesting on the second and third anniversaries of the March 14, 2025, reference date, subject to continued employment and accelerated vesting as provided in the applicable award agreement. The Reporting Person received DERs for each corporation restricted stock unit, providing for payment on the vesting date of a lump sum of cash equal to the accrued distributions from and after the grant date of the corporation restricted stock units.

The corporation restricted stock units and associated DERs do not expire. The corporation restricted stock units are settled upon vesting in common stocks (on a one-for-one basis) or in cash, at the discretion of the Issuer.

Common stocks being withheld to pay tax liability.

Common stocks being withheld to pay tax liability.