Machine-Readable File (MRF) Requirements: What Makes a File CMS-Compliant vs Noncompliant

Short answer: A Machine-Readable File (MRF) is CMS-compliant only if it can be programmatically parsed, computationally validated, and reconciled to real pricing outcomes. If a file requires explanation, interpretation, or manual cleanup, CMS treats it as noncompliant.

The legal authority for this requirement originates in 45 CFR Part 180, which establishes the obligation to publish standard charges in a machine-readable format. For statutory grounding, see:

→ 45 CFR Part 180 Explained: A deep dive into the specific law governing Price Transparency.

What CMS Means by “Machine-Readable”

CMS defines a machine-readable file as one that can be imported, processed, and analyzed by software without human intervention. This definition is enforced literally.

CMS Requirement	What It Means in Practice
Publicly accessible	No login, no forms, no CAPTCHA
Structured format	CSV, JSON, or XML only
Deterministic schema	Predictable fields, no ambiguity
Numeric pricing	Dollar amounts, not formulas

“If software cannot ingest it deterministically, CMS does not consider it disclosed.”

What a CMS-Compliant MRF Must Contain

CMS expects one canonical MRF per hospital location, containing all items and services with all required standard charges.

Required Element	CMS Expectation	Common Failure
Hospital identifier	Location-specific	System-wide rollups
Item/service identifier	CDM + billing code	Free-text descriptions
Revenue code	Explicit	Missing or inconsistent
Unit of measure	Defined	Implicit or assumed
Standard charges (all five)	Numeric values	Partial disclosure

For the legal definition of the five required prices, see:

→ What Counts as “Standard Charges” Under CMS Rules? A Legal and Technical Definition

What CMS Explicitly Rejects as Noncompliant

CMS enforcement experience has made one thing clear: intent does not matter—outputs do.

Noncompliant Pattern	CMS Interpretation
PDFs (even structured ones)	Not machine-readable
Percent-of-charge pricing	Not a price
“Call for estimate” entries	Missing data
Contract logic instead of numbers	Unverifiable
Aggregated payer rates	Misleading

“A file that explains prices instead of stating them fails CMS review.”

The July 2024 CMS v2.0 Inflection Point

In July 2024, CMS moved from format tolerance to schema enforcement. Files are now evaluated using automated validation logic.

CMS v2.0 Requirement	Enforcement Effect
Standardized schema	Custom formats rejected
Required field population	Missing data flagged
Numeric validation	Silent errors exposed
Cross-file consistency	Discrepancies detected

For the full technical breakdown, see:

→ CMS v2.0 Template Guide: Technical breakdown of the new mandatory July 2024 standards

“CMS v2.0 assumes your MRF will be machine-audited, not human-reviewed.”

Why Modifiers Matter in an MRF (January 2025 Forward)

Beginning January 2025, CMS expects MRFs to include Mod1, Mod2, and Mod3 where modifiers affect payment. Without them, prices cannot reconcile to claims.

Scenario	CMS View
CPT without modifiers	Ambiguous
Modifier affects payment	Must be disclosed
Modifier buried in notes	Treated as missing

For the full rationale, see:

→ The January 2025 Modifier Mandate: Why hospitals must now include Mod1, Mod2, and Mod3

How CMS Uses the MRF in Audits

CMS treats the MRF as the primary enforcement artifact.

CMS Action	How the MRF Is Used
Automated scans	Detect missing or malformed fields
Claims sampling	Test price realism
Warning letters	Cite specific file defects
CMP calculations	Accrue during noncompliance

For audit mechanics, see:

→ A CMS Audit Checklist for Hospitals

For financial exposure, see:

→ The Civil Monetary Penalty (CMP) Scale under Hospital Transparency Rules

Why Most Hospitals Fail MRF Compliance

Hospitals typically fail not because they lack data, but because they publish pricing abstractions instead of pricing reality.

Failure Mode	Root Cause
CDM-only pricing	No claims reconciliation
Contract-based logic	Non-numeric outcomes
Inconsistent units	Silent inflation
Missing modifiers	Adjudication mismatch

“A chargemaster-derived MRF is an input artifact, not a compliance artifact.”

Bottom Line

A CMS-compliant MRF is not a website deliverable. It is a claims-aligned, machine-verifiable representation of hospital pricing reality. CMS now evaluates these files at scale, without context, and without benefit of the doubt.

Hospitals that treat the MRF as a publishing task fail publicly. Hospitals that treat it as a pricing system pass quietly.

This article should be read alongside:

45 CFR Part 180 Explained: A deep dive into the specific law governing Price Transparency.
What Counts as “Standard Charges” Under CMS Rules? A Legal and Technical Definition
CMS v2.0 Template Guide: Technical breakdown of the new mandatory July 2024 standards
A CMS Audit Checklist for Hospitals