What does CO-167 mean?

CO-167 is a Contractual Obligation (CO) denial: "This (these) diagnosis(es) is (are) not covered." The diagnosis code itself isn't on the payer's covered list for this service — the issue is the diagnosis, not the procedure's necessity.

CO · Contractual ObligationCARC 167

Denial Code CO-167

Q: Is CO-167 the patient's responsibility or a provider write-off?

CO-167 carries the CO group code (Contractual Obligation): Provider/contractual responsibility — not billable to the patient while denied. A CO adjustment is the provider's responsibility, not the patient's: balance-billing the patient for a CO amount is a contract (and often compliance) violation. But CO does not automatically mean “write it off.” When the cause is fixable — missing information (CO-16), a modifier problem (CO-4), or NCCI bundling (CO-97) — you correct and resubmit, or appeal with documentation. You only truly write the amount off when it is a final contractual adjustment, such as the fee-schedule difference on CO-45.

This (these) diagnosis(es) is (are) not covered.

Source: X12 Claim Adjustment Reason Codes (CARC) & Group Codes. Maintained by the D3rx Clinical Billing Team.

What CO-167 means

The diagnosis code itself isn't on the payer's covered list for this service — the issue is the diagnosis, not the procedure's necessity.

Got this denial right now?

Fix & resubmit: see the CO-167 correction steps

See CO-167 correction steps Ask D3 about CO-167

CO-167 clears with a corrected claim, not an appeal. Ask D3 walks you through the exact fix — free, no signup.

CO group code: who absorbs the charge

Contractual Obligation — Provider/contractual responsibility — not billable to the patient while denied.

A CO adjustment is the provider's responsibility, not the patient's: balance-billing the patient for a CO amount is a contract (and often compliance) violation. But CO does not automatically mean “write it off.” When the cause is fixable — missing information (CO-16), a modifier problem (CO-4), or NCCI bundling (CO-97) — you correct and resubmit, or appeal with documentation. You only truly write the amount off when it is a final contractual adjustment, such as the fee-schedule difference on CO-45.

Why CO-167 happens

The submitted diagnosis isn't a covered indication under the payer's policy/LCD for the service
A screening diagnosis was used for a service that requires a medical (problem) diagnosis
A vague/unspecified diagnosis isn't recognized as covered for the procedure
A rule-out or non-billable diagnosis was reported where a confirmed condition is required

What to do when you get CO-167

1Identify which diagnosis triggered the denial via the remark code
2Check the payer's covered-diagnosis (LCD/policy) list for the service
3If a different, accurate diagnosis from the documentation is covered, submit a corrected claim
4If the submitted diagnosis is correct and should be covered, appeal with clinical documentation

Appeal, correct, or write off CO-167?

First confirm whether the documentation supports a covered diagnosis that simply wasn't the one billed — if so, a corrected claim is faster than an appeal. If the diagnosis billed is accurate and you believe the payer's coverage policy should include it, appeal with the chart notes and any policy citation. As with all diagnosis denials, never substitute an unsupported diagnosis to chase coverage.

Timing & deadlines

Corrected claims run against timely-filing limits (Medicare 12 months from date of service; commercial ~90-180 days); appeals run against the standard windows (Medicare 120 days; commercial ~180 days from the remittance).

Example

A lab test is billed with a screening diagnosis, but the payer's coverage policy lists only specific disease-state diagnoses as covered indications. The payer returns CO-167. If the patient's record documents a covered condition, a corrected claim with that diagnosis supports payment.

Prevent CO-167 going forward

Check covered-diagnosis lists (LCDs/medical policies) before ordering
Match screening vs. diagnostic intent to the correct diagnosis category
Use confirmed, specific diagnoses rather than rule-outs on claims
Maintain a crosswalk of common services to their covered indications

Code families most affected

Laboratory and pathology tests with covered-indication lists
Imaging studies governed by LCDs
Screening vs. diagnostic services

Related codes

Denial codes you'll often see alongside CO-167

CO-11 CO-50 PR-96

Payer notes

CO-167 says the diagnosis isn't covered, whereas CO-50 says the service isn't medically necessary and CO-11 says the diagnosis and procedure don't match — subtle but distinct. Coverage lists are payer- and policy-specific, so the same diagnosis can be covered by one payer and not another.

Fix this CO-167 denial the right way

CO-167 is resolved with a corrected claim, not an appeal. Ask D3 gives you the exact correction steps — free, backed by CMS, Medicare, and major-payer data.

See CO-167 correction steps Ask D3 about CO-167 All denial codes

Medical billing disclaimer

CARC/RARC definitions are the standardized X12 set; group-code semantics follow the X12 Claim Adjustment Group Code standard. Filing and appeal windows vary by payer — the standard anchors shown (Medicare redetermination 120 days from the remittance; Medicare timely filing 12 months from date of service; most commercial payers ~90-180 days) are general references, not a guarantee for any specific plan. Always confirm the rule in the payer's provider manual before acting. D3rx is not responsible for claim outcomes.