Claim denial

A denial is a decision, not a glitch. The payer received the claim, ran it through adjudication and decided it would not pay some or all of it. The decision comes back on the ERA or paper remittance with a group code, a claim adjustment reason code and often a remark code. X12 defines the group codes: CO for contractual obligation, PR for patient responsibility, OA for other adjustment and PI for payer-initiated reductions. The CARC says why (CO-50 for a service the payer does not consider medically necessary, CO-197 for a missing authorization, CO-4 for a code and modifier that do not fit), and the RARC adds detail.

Denials matter because each one has a clock and an owner. A denial stops the claim’s life unless somebody acts: send a corrected claim, supply records, request a reconsideration or file an appeal, each inside the payer’s own window. Denials also split into the kind that can be fixed and the kind that cannot, and the denial rate on your monthly report is the share of claims that were sent wrong the first time.

The mistake is reading the dollars and not the codes. Billers see a zero-pay line, post it as an adjustment and move on. Work denials from the CARC and RARC, group them by cause rather than by payer, and fix the upstream step (eligibility, authorization, coding, enrollment) that produced them.