Machine-readable file (MRF)

A structured data file, published by health insurers under the Transparency in Coverage rule, that discloses negotiated rates with in-network providers and historical out-of-network allowed amounts for all covered services.

Machine-readable files are the technical mechanism through which health insurers comply with the Transparency in Coverage rule's rate disclosure requirements. They are designed to be processed by software rather than read by humans — hence the name — and they contain the most comprehensive dataset of actual payor-provider negotiated rates ever made publicly available.

There are two primary MRF types required under the rule: the in-network rate file, which discloses negotiated rates for all covered items and services with in-network providers, and the allowed amount file, which discloses historical out-of-network payment data. A third file covering prescription drug pricing has separate implementation requirements.

The practical challenge of MRF data

While MRFs are technically public, they present significant practical challenges for any organization attempting to use them:

• Scale: A single major insurer's in-network rate MRF can exceed tens of terabytes of compressed data. Processing this data requires substantial technical infrastructure.
• Format inconsistency: While CMS has defined a technical schema for MRFs, insurers vary significantly in how they implement it — leading to inconsistencies in provider identification, billing code structure, and rate representation that require specialized handling.
• Data quality variation: The accuracy and completeness of MRF data varies considerably across insurers. Some files contain errors, outdated rates, or missing providers that must be identified and handled before the data can be used reliably.
• Ongoing maintenance: MRFs are updated monthly, meaning any analysis built on this data requires infrastructure for continuous ingestion and refresh.

MRFs as a source for payor rate benchmarking

For medical groups using payor rate intelligence for contract strategy, MRF data — properly extracted, cleaned, and vetted — is the most direct available source of information about what comparable practices in their market are being paid. It is the data that powers meaningful competitive benchmarking, and it is the reason that practices can now, for the first time, walk into a payor negotiation with evidence of what the market is actually paying.