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 can work out what a hospital actually charges, without asking the hospital first: a researcher, a journalist, a price-comparison tool, an employer negotiating a health plan, or a patient trying to understand a bill before it arrives.

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 and its code) can be read and challenged by anyone rather than taken on faith. That work hasn't started yet.