Accurate Medicaid data, delivered ahead of schedule

Improving data quality to meet new federal standards

State Medicaid programs are working to improve the quality of their Transformed Medicaid Statistical Information System (T-MSIS) data—the most complete set of Medicaid data available—to align with evolving federal requirements and support better insights for the Medicaid community. In June 2024, the Centers for Medicare & Medicaid Services (CMS) released updated T-MSIS data requirements, known as V4. CMS encouraged states to complete their transitions by September 30, 2025—well ahead of the late 2026 deadline—to allow time to address reporting or integration issues that may arise.

Data that states submit to CMS are required to be complete, accurate, timely, and properly formatted. States that do not meet CMS’s targets for data quality risk escalating oversight and potential financial penalties. To stay compliant while adapting to CMS’s new requirements, states and territories partner with Mathematica to review and strengthen the quality of their T‑MSIS data.

Upgrading Imersis for the next generation of T-MSIS reporting

To help states stay ahead of CMS’s timeline, Mathematica prepared Imersis, our cloud-based data quality tool, to be able to process and validate data in compliance with the new V4 T-MSIS data requirements. Imersis is designed to help state Medicaid agencies meet T-MSIS requirements by applying the same scoring logic that CMS uses. It provides state Medicaid agencies with data quality assessments within 24 hours of submission so they can find and fix issues before submitting data files to CMS for review.

To prepare for the new V4 T-MSIS data requirements, we:

• Updated the schemas in Imersis to support ingestion of data in the new layout.
• Identified and updated 80 of the existing critical, high-, and medium-priority data quality measures affected by CMS’s changes to prevent gaps in the data quality assessment.
• Coded 153 new validation rules to support data quality assessment of the newly required file type—Financial Transaction (FTX), which captures financial transactions previously reported in the claims files—so states can conduct more targeted testing.

By January 2025, Mathematica completed all necessary upgrades to Imersis so state Medicaid agencies could start testing their data quality under the new requirements. This was accomplished more than nine months before CMS’s recommended transition date.

Helping states achieve and sustain compliance

Three of Mathematica’s Imersis clients were able to test a combined 52 data submissions and ensure alignment with the new V4 T-MSIS requirements. Each client:

• Received CMS approval to submit its data to production by the September 2025 reporting period.
• Retained its “blue” status on CMS’s Outcomes Based Assessment map on Medicaid.gov, which shows that they met federal data quality expectations as they transitioned to the new data requirements.
• Sustained full compliance with the new T-MSIS data quality requirements after CMS resumed routine data quality compliance activities on December 1, 2025.
• Was recognized and congratulated by CMS as being early adopters of the updated data requirements.