CO-170: Payment Denied — Provider Type Not Eligible

What Does CO-170 Mean?

CO-170 is the most common pairing and means the provider type restriction results in a contractual write-off. The provider cannot bill the patient for the CO-170 amount. In most cases, the resolution involves correcting the billing identifiers (NPI, taxonomy) or rebilling under an eligible supervising provider. If the provider is genuinely ineligible for the service, the amount is a loss unless the service can be re-rendered or co-signed by an eligible provider.

When CARC 170 appears on a remittance, the payer has denied the claim because the type of provider who performed or billed the service is not authorized to receive payment for that specific procedure. This is not a question about whether the service was medically necessary or properly coded — the payer is saying that the provider's credentials, specialty, or enrollment status does not qualify them to bill this particular CPT or HCPCS code.

Payers maintain lists of which provider types are authorized for specific services. A nurse practitioner may be able to bill evaluation and management codes but not certain surgical procedures. A physical therapist may be restricted from billing certain diagnostic services. These restrictions vary significantly between payers and are often rooted in state scope-of-practice laws, payer contracts, and Medicare's provider type requirements. The RARC most frequently paired with this code is N95 ('This provider type/provider specialty may not bill this service'), which confirms the provider-type mismatch.

The most common resolution involves correcting the billing to use the right provider's NPI. In many cases, the service was legitimately provided but billed under the wrong provider — for example, a mid-level provider billed independently when the service should have been billed incident-to a supervising physician. In other cases, the rendering provider's enrollment with the payer may need to be updated to reflect the correct specialty or credentials. Always check the 835 Loop 2110 REF Healthcare Policy Identification Segment, which points you directly to the payer policy that triggered the denial.

Common Causes

How to Resolve

Identify the provider type restriction, verify credentials and enrollment, and either correct the billing identifiers or rebill under an eligible provider.

1. Check the payer policy Use the Loop 2110 REF and RARC N95 to identify the specific policy. Look up which provider types are authorized for the billed CPT/HCPCS code.
2. Verify and correct provider identifiers Check the NPI, taxonomy code, and enrollment status. Correct any mismatches and resubmit the claim.
3. Use incident-to billing if applicable If the service was provided by a mid-level and qualifies for incident-to billing, verify the requirements are met and rebill under the supervising physician.
4. Appeal with enrollment proof If the provider should be eligible, appeal with credentialing documentation, enrollment confirmation, and the relevant payer policy.

Common RARC Pairings

The RARC code tells you exactly what triggered the CO-170:

How to Prevent CO-170

• Maintain an up-to-date matrix of which provider types can bill specific CPT/HCPCS codes for each major payer
• Verify provider enrollment and credentialing status before billing under their NPI
• Implement claim scrubbing that cross-references provider taxonomy codes against procedure codes
• Ensure incident-to billing requirements are met before submitting under a supervising provider
• Monitor payer policy changes affecting provider type eligibility

General Prevention

• Maintain an up-to-date reference of which provider types are authorized to bill specific CPT/HCPCS codes for each major payer
• Verify provider credentialing and enrollment status with each payer before billing services under that provider's NPI
• Implement claim scrubbing that checks the rendering provider's taxonomy code against the billed procedure code to catch provider-type mismatches
• Ensure incident-to billing requirements are met before submitting claims under a supervising physician's NPI
• Train billing staff on payer-specific provider type restrictions and scope-of-practice rules
• Monitor payer policy updates that may change which provider types can bill specific services

Also Filed As

The same CARC 170 may appear with different Group Codes:

Related Denial Codes