About Care Carta

CMS runs its own validator against a hospital's file, confirming the file's structure matches the required format. Care Carta starts from that same validator, then goes further: it confirms the file actually belongs to the hospital it claims to (matching the hospital's own identifiers), that it downloads the way the rule requires — no login, no payment, machine-readable, discoverable from the hospital's own site — and that it stayed that way the next time it checked. A hospital can pass CMS's validator and still fail these checks.

Care Carta only checks what a machine can verify from the outside, against the rule's own text. It cannot see a hospital's actual negotiated contracts, cannot confirm a listed price is accurate, and carries no CMS or legal enforcement authority — it can only report what it observed. A "couldn't determine" result means the check needed evidence Care Carta doesn't have access to, not that the hospital passed. See our legal disclaimer.

The machine-readable file is the one artifact the rule actually requires: a listing, for every item and service a hospital bills for, of its gross charge, its discounted cash price, and the rates it has negotiated with every payer it accepts. It exists so that anyone — a researcher, a journalist, a price-comparison tool, an employer negotiating a health plan, a patient trying to understand a bill before it arrives — can work out what a hospital actually charges, without asking the hospital first.

Anyone who wants a factual answer to "does this hospital publish what it's supposed to, and does it work the way the rule requires": researchers and journalists building on the files, other tools that consume them, hospital compliance teams checking their own posture, and patients trying to judge whether a price they were quoted matches what's published.

Care Carta currently audits hospitals only, under 45 CFR Part 180. It does not yet audit health plans' machine-readable files under the separate Transparency in Coverage rule, and has no view into a payer's own data.

Care Carta is planned to be open source, so the audit itself — its rules, its evidence, its code — can be read and challenged by anyone rather than taken on faith. That work hasn't started yet.