What changed in CMS schema v3.0
Three substantive additions, effective January 2026.
1. Median, 10th, and 90th percentile allowed amounts
The old "estimated allowed amount" placeholder is gone. In its place, hospitals must report the median, 10th percentile, and 90th percentile allowed amounts derived from actual EDI 835 remittance data over a 12 to 15 month lookback, plus the count of amounts behind each calculation. A percentile field with no count, or a 10th percentile that's higher than the median, is a structural error, not a rounding quirk.
2. Organizational Type 2 NPIs
For taxonomy codes beginning '27' or '28', the file must carry the organization's Type 2 NPI, active as of the most recent update. A structurally invalid NPI (failing the standard checksum) or one that doesn't resolve to an active organizational record in NPPES both break this requirement, for different reasons.
3. The attestation encoding itself
The attestation is no longer a generic compliance line. It now carries a named signing official. See our attestation guide for the full detail.
A quirk worth knowing about
In the CSV Tall and Wide formats, the attestation text is not stored under a column literally named "attestation". The metadata header row's eighth column is the attestation sentence itself, used as the column name, and the value beneath it is just a confirmation flag. Tooling that looks for a column named "attestation" will silently miss it. We learned this the hard way building our own parser against real hospital files.
See the exact rules we check against the v3.0 schema.
View all checks