NOTICE DATE: April 1, 2026

NOTICE TYPE: M-B040126-01 Operations

SHORT DESCRIPTION: Incorrect Reliability Unit Commitment (RUC) Opt- Out Snapshot Logic Issue Identified

INTENDED AUDIENCE: All Market Participants

DAYS AFFECTED: March 23, 2026

LONG DESCRIPTION: On March 23, 2026, a logic error in the Opt-Out Snapshot caused the buyback flag to be incorrectly set to "N" for some Reliability Unit Commitment (RUC)-committed resources. ERCOT has developed a fix and intends to implement it on April 2, 2026.

This issue occurs when ERCOT operators extend RUC commitment hours to a start time earlier than the RUC recommended start time. In this scenario, the Opt-Out snapshot logic bypasses the Opt-Out snapshot check. 

ERCOT has reviewed the impact and, pursuant to Nodal Protocol 6.3(4), cannot correct prices as ERCOT cannot determine accurate prices.

CONTACT: If you have any questions, please contact your ERCOT Account Manager. You may also call the general ERCOT Client Services phone number at (512) 248-3900 or contact ERCOT Client Services via email at ClientServices@ercot.com.

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