Upcoming Change to CAISO Annual Functional Release Schedule, effective 2027

California ISO is providing early awareness of a change to the timing of its annual functional release. Beginning in 2027, the release will move from its traditional Fall schedule to a Spring cycle, with a current target of May 1, 2027. This shift is intended to improve planning and coordination across market participants, allow more time for development and testing, and enhance overall implementation readiness.

Impacted audience

This change impacts Scheduling Coordinators, Generator Owners, Market Participants, EDAM/WEIM participants, vendors, and stakeholders involved in system updates, testing, market readiness, release coordination, and onboarding.

What is a Functional Release?

A functional release is a planned update that introduces new features, enhancements, and system improvements to CAISO’s market and operational systems. These releases are essential for maintaining reliability, advancing market initiatives, and meeting regulatory requirements.

What Is Changing

New cadence: The annual CAISO functional release will shift from Fall to Spring.
Timeline: Specific release dates are still being finalized and will be communicated once confirmed.
Impact: This change may affect planning cycles, testing schedules, and stakeholder coordination.

Reason for the Change

Supports summer readiness: Moving the release to Spring ensures new functionality is in place well before peak summer demand.
Improves onboarding timing: Shifting EDAM/WEIM onboarding to the Fall allows for a smoother post-summer transition and reduces risk during high-demand periods.

We appreciate your attention to this change and will continue to share updates, including confirmed dates, transition details between Fall 2026 and Spring 2027, and any adjustments to testing and coordination activities.

Resources

Release User Groups (RUG) Forums provide opportunities to ask questions and share feedback. Please visit ISO's website for upcoming meeting dates.

Contact information

Please contact Trang Vo at release@caiso.com with any release related questions.