How do I fix a CO-11 denial?

Pull the LCD/policy article for the item and match the covered dx list Query the ordering physician for the precise diagnosis; resubmit with the supported code

CO-11 — Diagnosis inconsistent with the procedure

Claim-adjustment reason code 11 · typically reported as CO-11

What it means

The diagnosis billed doesn’t support the item per the payer’s coding rules — the dx-to-HCPCS pairing failed an edit.

Why DME claims hit it

CPAP (E0601) billed without an obstructive sleep apnea diagnosis
Oxygen billed with a dx that doesn’t support hypoxemia
Generic "unspecified" dx codes where the LCD requires specificity

How to fix it

Pull the LCD/policy article for the item and match the covered dx list
Query the ordering physician for the precise diagnosis; resubmit with the supported code

Appeal posture

If the medical record supports a covered dx that simply wasn’t on the claim, correct and resubmit; appeal with records if the payer rejects a legitimately covered dx.

Related denial codes

CO-50 — Not deemed medically necessary CO-167 — Diagnosis not covered CO-146 — Diagnosis invalid for the date of service

Looking up an item instead? Browse the HCPCS code library for fee schedule amounts and PA flags.

Turn denials into recovered revenue

MyMedi-AI maps every remit code to its fix, tracks appeal deadlines, and drafts appeal letters with the right documentation checklist.

Start free trial Run a CMS-0057-F readiness check