NOTICE DATE: February 13,2026

NOTICE TYPE: M-B021326-01 Operations

SHORT DESCRIPTION: Impacts to Generic Transmission Constraint Limits in the Day-Ahead Market due to a software issue.

INTENDED AUDIENCE: All Market Participants

DAYS AFFECTED: February 1, 2026 to February 7, 2026

LONG DESCRIPTION: A software issue in our Energy Management System (EMS) led it to use the previous week's network model when calculating Generic Transmission Constraint limits for Operating Days (OD) February 1 to February 7, 2026. This caused some transmission limits to be inaccurate in the Day-Ahead Market (DAM). We implemented a temporary workaround on February 6 that corrected calculations in the DAM starting on OD February 8. On February 11, we deployed a permanent software fix.

We cannot accurately recreate the necessary input datasets in EMS for ODs February 1 - 7, 2026. Therefore, we cannot perform a price correction for those Operating Days.

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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