Every
denial arrives with a Claim Adjustment Reason Code (CARC) that tells you exactly why the
payer denied or adjusted the claim. Effective denial management starts by categorizing every denial by its CARC code and mapping it to a root-cause category. Eligibility denials (25% of all denials, CARC codes CO-4, PR-1, PR-2, CO-27): the patient was not covered, the plan changed, or the
deductible had not been met. Root cause is a front-end verification failure.
Authorization denials (15%, CO-15, CO-197):
prior authorization was not obtained, expired before the service date, or did not cover the specific procedure performed. Root cause is either a scheduling-workflow failure or a payer-requirement knowledge gap. Coding denials (15%, CO-16, CO-97, CO-11): wrong CPT or ICD-10 code, missing
modifier, CCI
bundling violation, or diagnosis-procedure mismatch. Root cause is a coding-quality or claim-scrubbing failure.
Medical necessity denials (10%, CO-50): the payer disagrees that the service was medically necessary based on the submitted diagnosis. Root cause is either insufficient documentation or incorrect diagnosis linkage.
Timely filing denials (10%, CO-29): the claim was submitted after the payer's filing deadline. Root cause is a workflow failure. claims were batched rather than submitted daily. Other (25%): duplicate claims, incorrect patient demographics, coordination-of-benefits issues, and payer-system errors. Track denial volume and dollar amount by CARC code monthly. The category with the highest dollar volume is where you invest process-improvement effort first.