Revenue Cycle Denials: The Five Codes That Account for 60% of Lost Revenue

Across mid-size practices, five Claim Adjustment Reason Codes (CARCs) account for roughly 60% of denial dollars. The codes don't change much year to year. What changes is which one is growing — and growth in any of the five is a leading indicator of a workflow problem.

1. CARC 197 — Precertification / authorization absent

Service was provided without required authorization. This is a front-end issue, not a back-end one — appeals are uphill. Growth in CARC 197 usually points to a new payer policy (a previously-approved service now requires prior auth) or a workflow gap (the auth queue isn't catching new patients).

Fix: weekly review of new prior-auth requirements by payer, and a denied-vs-pre-authorized cohort report that pinpoints which front-end step failed.

2. CARC 16 — Claim/service lacks information

Documentation is missing a required field. The payer doesn't tell you which field; the appeal requires you to find it. Growth in CARC 16 usually means a template change (an EHR update changed which fields populate the claim) or a credentialing change (the provider's NPI is mis-linked).

3. CARC 18 — Duplicate claim/service

Almost always a clearinghouse routing or resubmission workflow issue. Real duplicates are rare; reported duplicates are common. Growth signals a clearinghouse problem, not a billing problem.

4. CARC 109 — Claim not covered by this payer/contractor

The patient's coverage doesn't match what was billed. Usually a front-end eligibility verification issue. Growth in CARC 109 is a leading indicator that your eligibility check workflow is missing a payer change.

5. CARC 50 — Medical necessity

The service was provided but the payer rejects medical necessity. These are appealable but appeals require clinical documentation review and time. The economic question: which CPTs are most often denied for CARC 50, and is there a documentation pattern that prevents the denial up front?

The analytics view that catches them early

Most denial dashboards report cumulative denial dollars by code, year-to-date. That number is true but useless — it tells you nothing about whether a problem is growing. The view that actually drives intervention is week-over-week change in denied dollars by CARC, by payer.

When CARC 197 denials with Anthem grew 40% week-over-week in late October, that's the signal — usually a new prior-auth policy that started October 1. Catch it in October, recover the revenue in November. Catch it in February, you've eaten four months of denials.

What the analytics layer should do

Vizier's revenue cycle module ships with CARC trending pre-built. Connect your EHR or billing system and the five codes above become a single dashboard with week-over-week change, payer breakdown, and the patient/encounter list you need to act on.

The pattern that beats the 60%

Practices that consistently keep total denial rate below 5% (the best-in-class threshold) share one habit: they review denied dollars by CARC weekly, not monthly. The denials cost the same money either way; the question is whether you find out in time to fix the workflow.