277CA claim acknowledgment

Medicare’s EDI manual names two transactions for acknowledging the claims it receives: the 999 for the file and the 277CA for the claims inside it. After a file passes the syntax checks, the payer’s front end runs its business edits, and the 277CA reports the result claim by claim. Claims with data in error are flagged back to the submitter on it, and accepted claims move on to the claims processing system. The 277CA is built on the X12 277, in version 005010X214. HIPAA does not require it, but Medicare uses it with the 999 and the TA1 as its acknowledgment model¹. Its answers come as codes: CMS requires Medicare to use valid claim status category codes and claim status codes in the 277CA, as it does in 277 claim status responses⁴. The category list, which X12 publishes, sorts those status codes into groups³.

For an accepted claim, the 277CA carries the claim control number the payer assigned, the ICN or DCN in Medicare terms. CMS hands that number back at this stage so a submitter can ask about individual claims instead of whole files¹. For a rejected claim, the status codes point to the data that failed^1,4. A rejection is not a denial: CMS sends rejected claims back for correction and resubmission, while denials come out of its coverage and payment policy edits².

The mistake is stopping at the 999. A file can pass the 999 while claims inside it fail on the 277CA, and those claims will never appear on an 835. Match each 277CA to the batch that produced it, and work the rejections the same day they arrive.