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CO-170 Denial Code: Not Payable to This Provider Type

CO-170 means payment is denied because the service was performed or billed by a provider type the payer does not pay for that service. It usually traces to provider taxonomy, scope of practice, credentialing, or the payer's policy on who may bill the code.

Quick facts

Code
CO-170 (CARC 170)
Status
Active In use since June 30, 2005; last modified July 1, 2017.
Code set
Claim Adjustment Reason Codes (CARC)
Group codes
  • CO (Contractual Obligation): The provider is responsible for the denied amount. It is not billable to a network patient.
  • PR (Patient Responsibility): Rare. The plan may make the patient responsible when the member chose a provider type the plan does not cover. Check the plan and any required notice.
Official description
Payment is denied when performed/billed by this type of provider. Usage: Refer to the 835 Healthcare Policy Identification Segment (loop 2110 Service Payment Information REF), if present.
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What CO-170 means

CARC 170 reads “Payment is denied when performed/billed by this type of provider.” The payer has rules about which provider types can be paid for a service. For example, some services can only be billed by physicians, some plans do not cover certain licensed counselors, and some procedures are limited to specific specialties. When the rendering or billing provider type on the claim is not permitted, the claim is denied.

The usage note refers to the 835 Healthcare Policy Identification segment (loop 2110 REF). If the payer includes it, it identifies the policy that lists allowed provider types.

Example: a behavioral health group bills psychotherapy rendered by a licensed counselor under a plan that does not credential that license type. The payer denies the line with CO-170 and remark N95.

Common causes

  • Taxonomy code mismatch between the claim and the provider’s enrollment with the payer.
  • Wrong rendering NPI in box 24J, such as a supervising physician’s type being expected but the clinician’s NPI reported (or the reverse).
  • Provider type not covered by the plan (certain counselor, therapist, or assistant types under some plans).
  • Scope of practice limits under state law or payer policy for the service billed.
  • Group billing an individual not enrolled with the payer as a rendering provider.
  • Incident-to or supervision rules applied incorrectly.

How to fix it

  1. Check the rendering NPI (box 24J) and taxonomy on the claim against the provider’s enrollment record with the payer.
  2. Read the payer’s policy for the service to see which provider types can bill it.
  3. If the NPI or taxonomy was wrong, submit a corrected claim with resubmission code 7 in box 22.
  4. If the provider isn’t enrolled or credentialed, start or fix enrollment; ask whether retroactive effective dates are possible.
  5. If the policy allows billing under a supervising provider, confirm the supervision and documentation requirements are met before rebilling.
  6. Appeal only if the provider type is allowed by policy or contract and the payer misapplied it.

How to prevent it

  • Verify enrollment and taxonomy for every new clinician with each payer before scheduling patients.
  • Keep NPPES taxonomy data current and consistent with payer enrollment.
  • Map services to allowed provider types per payer for your specialty.
  • Check rendering provider rules during claim scrubbing. See provider enrollment and NPI denials.
  • Monitor denials by rendering provider to catch a single clinician’s setup problem early.

Specialty notes

Behavioral health practices see CO-170 frequently because payer coverage of counselor, marriage and family therapist, and associate-level license types varies widely. PT/OT practices can see it with assistants billing independently.

Remark codes that may appear with CO-170

  • N95 (This provider type/provider specialty may not bill this service.): The provider type or specialty may not bill this service.
  • N290 (Missing/incomplete/invalid rendering provider primary identifier.): The rendering provider identifier is missing or invalid, which may make the payer see the wrong provider type.
  • N570 (Missing/incomplete/invalid credentialing data.): The credentialing or enrollment information for the provider is missing or invalid.
  • CO-171 (Payment is denied when performed/billed by this type of provider in this type of facility.): Denied for this provider type in this type of facility, a narrower rule.
  • CO-172 (Payment is adjusted when performed/billed by a provider of this specialty.): Payment adjusted, not denied, because of the provider's specialty.
  • CO-185 (The rendering provider is not eligible to perform the service billed.): The rendering provider is not eligible for the service billed.
  • CO-B7 (This provider was not certified/eligible to be paid for this procedure/service on this date of service.): The provider was not certified or eligible to be paid for the procedure on that date.

CO-170 FAQ

What is a provider taxonomy code and why does it matter?

It is a code identifying the provider's type and specialty, reported in the 837 and tied to the NPI record. Payers compare it to the services billed; if the taxonomy does not match an allowed provider type, the claim may be denied.

Can a nurse practitioner or therapist trigger CO-170?

Yes, if the payer does not recognize that provider type for the service or does not credential that type at all. Some plans require services by certain provider types to be billed under a supervising physician, while others prohibit that.

Is CO-170 fixed with a corrected claim?

Sometimes. If the wrong rendering NPI or taxonomy was reported, a corrected claim may resolve it. If the provider type genuinely is not covered, a corrected claim will not help.