26-690 Monthly Membership Report Detail Data File Layout Change, Effective July 2026
Date: 05/22/26
Certain fields expanded from 7 to 8 bytes to improve payment accuracy and risk data
Starting in July 2026, certain fields in the Monthly Membership Report Detail (MMRD) data file will be updated. These changes are designed to improve the accuracy of payment and risk data for Medicare Advantage (MA) members.
What is changing
The field length will increase from 7 bytes to 8 bytes for the fields below:
- Risk Adjustment Factor A – Used for Part A payment calculations
- Risk Adjustment Factor B – Used for Part B payment calculations
When this takes effect
This change will apply to the July 2026 MMRD file and to all payments going forward. The updated layout for the MMRD data file will be sent to participating physician groups on June 22, 2026.
Why this matters
The MMRD data file is used to track:
- Capitation payments and adjustments.
- Monthly enrollment information.
- Risk adjustment factors for MA and Part D members.
Resources
For more information about this change, refer to the Centers for Medicare & Medicaid Services notice dated April 20, 2026.
Need help?
If you have questions or need assistance, email Capitation Department.
This information applies to Participating Physician Groups (PPGs).