CO-96 denial code
Non-covered charge. The service is not a benefit under the patient's plan at all — this is different from 'not medically necessary', which is CO-50.
CO — Contractual Obligation. The write-off is yours. You agreed to it in your contract with the payer, and you cannot bill the patient for it.
Why you got it
- 1The service is genuinely excluded from the plan's benefits.
- 2The service is statutorily excluded (Medicare does not cover it for anyone).
- 3A coding error made a covered service look like a non-covered one.
How do I fix a CO-96 denial?
- Check first whether the service is truly non-covered or whether the coding made it look that way.
- If an ABN was signed, bill the patient with the appropriate modifier. If not, you absorb it.
- Statutory exclusions cannot be appealed. Benefit exclusions rarely can.
How to stop the next one
Know before the service whether it is covered, and get the ABN signed if it is not. Afterwards is too late to ask.
Our diagnosis scrubber will not catch this one. CO-96 is driven by procedure codes, modifiers, or eligibility rather than by the diagnosis set — and procedure-side checking needs an AMA CPT licence we do not hold yet. We would rather tell you that than sell you a tool that quietly misses your most common denial.
If denials like this are a volume problem rather than a one-off, the denial management page explains how the paid workspace catches the coding causes on every claim, and the free ICD-10-CM lookup shows the coding notes behind any diagnosis code on the remittance.