Denial Code CO-96

What CO-96 means

The service isn't covered, and under the CO group code the provider — not the patient — absorbs the charge (often because no valid advance notice was given).

CO group code: who absorbs the charge

Why CO-96 happens

• A statutorily excluded or plan-excluded service was billed without valid patient notice (e.g., no ABN on file for a Medicare non-covered service)
• The diagnosis submitted does not establish coverage for the service
• A frequency/coverage limit was exceeded and the provider is liable
• A service that requires a specific covered indication was billed without it

What to do when you get CO-96

1. 1Read the paired RARC — it states why the charge is non-covered
2. 2Check whether a covered diagnosis or correct procedure code applies and submit a corrected claim if so
3. 3Determine liability: for a service Medicare usually covers but denied here (e.g., medical necessity), you need a valid ABN to bill the patient; for a service Medicare never covers (statutory exclusion) the patient is liable regardless, and a voluntary ABN is recommended but not required
4. 4If you believe it IS covered, appeal with clinical documentation

Appeal, correct, or write off CO-96?

First decide whether this is a coding fix or a coverage fight. If the wrong (or insufficiently specific) diagnosis or procedure code drove the non-coverage, a corrected claim is faster than an appeal. If the service was genuinely covered, appeal with documentation establishing medical necessity and the covered indication. Because CO-96 lands the charge on the provider, the key distinction from PR-96 is whether valid advance notice exists — without it, you write off rather than bill the patient.

Example

A provider bills a screening service that the plan covers only for a specific risk diagnosis, but submits a general diagnosis instead. The payer returns CO-96 (non-covered). Because no ABN was issued, the practice cannot bill the patient; submitting a corrected claim with the qualifying diagnosis (if clinically accurate) is the right move.

Prevent CO-96 going forward

• Verify coverage and covered diagnoses before scheduling discretionary services
• Issue an ABN/advance notice for likely-non-covered Medicare services to preserve patient billing
• Check frequency limits before repeating preventive/screening services
• Map each elective service to its covered indications in your charge templates

Code families most affected

• Preventive and screening services with covered-indication rules
• Statutorily excluded services (Medicare)
• Frequency-limited services

Related codes

Payer notes

CO-96 and PR-96 share CARC 96 ('non-covered charge(s)') — the group code is what changes who pays. CO-96 = provider liability (e.g., a usually-covered service denied for necessity with no valid ABN on file); PR-96 = patient liability (valid ABN, or a statutorily excluded service the patient owes regardless). Per X12, CARC 96 must be accompanied by at least one Remark Code explaining the non-coverage.