How these files are graded

Every check is deterministic, cites the CMS hospital price-transparency rule (45 CFR part 180, in particular § 180.50) or the CMS schema documentation, and can be explained in one sentence. There is no model anywhere in the grading path.

What is checked

Five independent dimensions per file: retrievability (one identified, bounded download attempt), conformance (selected CMS v3 envelope, structure, and accepted-value checks), completeness (presence and usability of the fields that make a rate interpretable), interpretability (whether rates are usable amounts or require separate treatment), and freshness (the file's own last_updated_on against the assessment date). The complete finding catalog with citations is in docs/how-we-grade.md.

What is deliberately not checked

• This is not the official CMS validator and not exhaustive schema validation; an A means the implemented checks emitted nothing, not that the file is valid.
• No determination of legal compliance with 45 CFR part 180 or any other law.
• No verification that published prices, payer names, or attestations are factually accurate.
• No price comparison of any kind: dollar, percentage, and algorithm rates are structurally separated, and no rate statistic is published without the suppression and uncertainty work this project has not yet done.
• No long-run availability measurement: retrievability reflects one bounded attempt from one vantage on one date.

The letter grade

Grade policy cms-hospital-json-v3-file-grade-v1, fingerprint e2e3f8d32fcaecf5…. The full rule table ships in the machine-readable comparison. In evaluation order: a failed download is an F with the dated reason; a local limit (invalid input, the project's size ceiling, cache trouble) is not graded and never conflated with an F; an incomplete stream is an F; then errors (or missing evidence) in zero dimensions is an A (warnings make it a B), one dimension a C, two a D, three or more an F. Tolerated INFO observations never lower a grade.

How this cohort was collected

One serial, operator-invoked run of `mrf-honest scorecard` per target under the default retrieval policy: identified User-Agent with a contact address, HTTPS only, conditional revalidation against the verified cache, retry backoff, and the default 1 GiB decoded-size ceiling. One bounded GET per file, with a pause between requests. An earlier same-day pass under a lower 500 MB ceiling was superseded by this run; its rows remain in the operator registry and fall outside this cohort's retrieval-policy scope.

Hosts' robots.txt files were checked for every retrieved URL before the run; a site that blocks is recorded and skipped, never circumvented. Retrieval of these files is what the transparency rule exists to allow: CMS requires them to be public, machine-readable, and accessible without barriers.

Finding codes emitted in this cohort

A grade describes one published file under one stated policy on one date. It does not rank hospitals, price care, or determine compliance with 45 CFR part 180, and it is not the official CMS validator.