For hospital payer-specific negotiated charges based on a percentage or algorithm, CMS replaced the estimated allowed amount with the median allowed amount and added the 10th and 90th percentile allowed amounts, plus an observation count.
Hospitals calculate these values from electronic remittance advice or equivalent data over a 12-15 month lookback period. The revisions also add organizational NPI reporting and a hospital attestation about the file's accuracy and completeness.
These are observed allowed amounts for the hospital's reported services and payer arrangements. They are not national market percentiles, and they do not establish what another provider should be paid.
The changes took effect January 1, 2026. Enforcement began April 1, 2026. Read the CMS policy changes.