CO-167 Denial Code: Diagnosis(es) Not Covered
CO-167 is a claim adjustment reason code meaning this diagnosis or these diagnoses are not covered. The ICD-10 code on the claim is not on the payer's covered-diagnosis list for the billed procedure. Most fixes involve reviewing the record for a more specific, accurate diagnosis or appealing with the LCD/policy criteria.
- Group
- CO (Contractual Obligation)
- Category
- Diagnosis / coverage policy
- Appealable?
- Yes, when documentation supports a covered diagnosis or criteria
- Typical fix
- Recheck chart for accurate specific dx; correct claim or appeal with policy
What does denial code CO-167 mean?
CO-167 means "this (these) diagnosis(es) is (are) not covered." The payer matched your CPT code against the ICD-10 code(s) on the claim and found the diagnosis missing from its covered list for that service. Coverage lists live in Medicare NCDs and LCDs and in commercial medical policies, and they are code-specific down to the character.
Example: a podiatrist bills 11721 (debridement of 6 or more nails) at $92.00 with M79.673 (foot pain) as the only diagnosis. The LCD for routine foot care requires a qualifying systemic condition such as diabetes with complications. ERA: billed $92.00, allowed $0.00, CO-167 $92.00, paid $0.00. The chart actually documents E11.42, diabetic polyneuropathy, which is on the covered list; it just never made it onto the claim.
Why did the claim get a CO-167?
- Under-specific coding. The record supports a covered, more specific code, but an unspecified or symptom code went on the claim.
- Wrong diagnosis pointer. The covered dx is on the claim but not pointed at the denied line.
- Screening vs. diagnostic confusion, where a diagnostic ICD-10 was used for a screening service or vice versa.
- Policy changes. LCDs and commercial policies revise their covered-dx lists; a combination that paid in March can deny in April.
- Genuinely non-covered indication, where the payer does not cover the service for this condition at all.
How do you fix and resubmit a CO-167 denial?
- Pull the payer's coverage policy for the CPT and read the covered ICD-10 list.
- Reread the encounter note. Look for documented conditions that are on the list, and for specificity the coder left on the table (laterality, complication characters, underlying disease).
- If the record supports a covered diagnosis, correct the claim, fix the pointers, and resubmit as a corrected claim.
- If the documentation is thin but the condition existed, query the provider for an addendum before rebilling; never code beyond the note.
- If the indication truly is not covered, handle it like a non-covered service: patient notice going forward, write-off or patient billing per the group code and your contract.
How do you prevent CO-167 denials?
Load procedure-to-diagnosis edits from your top payers' policies into your scrubber so mismatches are flagged before submission. Subscribe to LCD revision notices for your specialty's core codes and recheck cheat sheets quarterly. Train providers on specificity for your top 10 procedures, and audit unspecified-code usage monthly; a high unspecified rate is the leading indicator of CO-167 (and of medical necessity denials generally).
Can you appeal a CO-167 denial?
Yes, when the documentation supports coverage. The strongest appeals do two things: map the chart to the policy's covered diagnosis list (quote the note, cite the exact ICD-10 from the list), or challenge the policy application when the patient meets the coverage criteria narrative even if the code mapping was imperfect. Attach the relevant note pages, not the whole chart. Confirm timing with the appeal deadline calculator, draft with the appeal letter generator, and verify the remark codes in the denial code lookup first; some payers pair 167 with remarks that identify exactly which dx failed.
Frequently asked questions
The payer does not cover the billed service for the diagnosis submitted. The ICD-10 code failed the payer's covered-diagnosis list for that CPT, usually defined in an LCD, NCD, or commercial medical policy. It is a diagnosis-to-procedure match problem, not a question about the procedure itself.
Only if the medical record actually supports it. Swapping in a payable diagnosis the chart does not document is fraud. The correct move is to reread the note: providers often document a covered, more specific condition that was coded too vaguely. Code what is documented, never what pays.
CO-50 says the service is not deemed medically necessary by the payer, a judgment about the service given the whole picture. CO-167 is narrower: the specific diagnosis code is not on the covered list for that procedure. CO-167 often resolves with more accurate coding; CO-50 usually needs a medical necessity appeal.
Sources & further reading
Reviewed by the ImmediCare Solutions RCM team
Certified billers and coders handling claims across 50+ specialties nationwide. This entry is reviewed against current payer policy and CMS rules. Last review: Jul 5, 2026.
Stop losing revenue to problems like this.
A free billing audit shows exactly where your practice is leaking money — no cost, no commitment.
