CO-170 denial code
Payment denied when performed or billed by this type of provider
How to fix it
Verify the rendering provider's enrollment and specialty designation with the payer. Correct the provider on the claim if it was submitted under the wrong NPI.
How to prevent it
Confirm scope-of-service eligibility during credentialing, not after the first denial.
In practice
A clinic bills a diagnostic procedure performed by a nurse practitioner. The claim returns CO-170: payment denied when performed or billed by this type of provider.
The practitioner is licensed and enrolled. What the payer is saying is narrower — this provider type is not eligible to bill this particular service under this plan, regardless of enrolment.
The first thing to check is whether the claim went out under the right NPI at all. Where the provider is correct, the question becomes whether the service is payable under a supervising physician instead, and whether the encounter genuinely met that arrangement's requirements.
What sits behind it
CO-170 is about scope rather than credentials, which is why re-checking enrolment usually finds nothing wrong. Enrolment establishes that a provider may bill the payer; scope establishes which services they may bill for, and payers set that independently of state licensure.
It concentrates around non-physician providers and around specialty designations. A payer may pay a nurse practitioner for evaluation and management and decline the same practitioner for a procedure, or decline a service because the enrolled specialty on file does not match the service billed.
The dangerous response is rebilling under a supervising physician to clear the denial. Incident-to and supervision arrangements have specific requirements — an established patient, an existing plan of care, direct supervision — and asserting them after the fact, when they were not met, converts a payment problem into a compliance one.
Related codes
Terms used here — Credentialing · NPI · CPT Code
How we handle it — Provider Credentialing · Denial Management · Medical Coding
Primary sources
The rules behind CO-170, at the bodies that publish them.
- PECOS Medicare enrollment (opens in a new tab)
Centers for Medicare & Medicaid Services — Where Medicare provider enrollment is filed and maintained. Revalidation deadlines missed here stop payment outright.
- Medicare Claims Processing Manual (opens in a new tab)
Centers for Medicare & Medicaid Services — The operative manual for how Medicare claims must be coded, submitted, adjusted and appealed. When a payer policy and a vendor's advice disagree, this settles it.
- Medicare Benefit Policy Manual (opens in a new tab)
Centers for Medicare & Medicaid Services — What Medicare covers and under what conditions, as distinct from how a claim is processed. The starting point for any coverage or medical necessity question.
Looking for a different code? Search all 190 CARC and RARC codes
Questions about CO-170
Both concern provider eligibility, but CO-185 usually means the rendering provider is not enrolled or eligible at all, while CO-170 means this type of provider is not eligible for this particular service. One is a credentialing gap; the other is a scope limitation.
Because enrolment and scope are separate. Enrolment says a provider may bill the payer; scope says which services they may bill for. Payers set scope independently of state licensure, so a licensed and enrolled practitioner can still be outside scope for a specific procedure.
Only where the encounter genuinely met that arrangement's requirements at the time — an established patient, an existing plan of care and direct supervision. Asserting incident-to after a denial, when the conditions were not met, is a compliance exposure rather than a fix.
Confirm scope of service per provider per payer during credentialing, not after the first denial, and load it so a claim cannot go out under a provider the payer will not pay for that service.
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