CO-170 Denial Code: Denied for This Type of Provider, Explained

The CO-170 denial code means the payer denied payment because the service was performed or billed by this type of provider. The service may be payable, just not from the provider category, facility type or bill type that sent it. Medicare uses CO-170, for example, when annual depression screening arrives on an institutional bill type it does not cover. The CO group makes the denied amount a provider write-off unless you reroute or overturn it.

What is the CO-170 denial code? CO-170 is a Claim Adjustment Reason Code (CARC) meaning payment is denied when the service is performed or billed by this type of provider, used when a policy limits a service to certain provider, facility or bill types.

Undeny's Take

CO-170 is a routing denial. It does not say the patient did not need the service; it says the claim came from the wrong kind of biller. That makes the remark code your map: N428 ("Not covered when performed in this place of service") points to the setting or bill type, while N95 points to provider type or specialty. In CMS's own instructions, the fix is usually structural: send the service on a bill type the policy covers, or from the entity type allowed to bill it, provided that entity actually furnished it. Appeals win only when you can show the policy already allows your provider or bill type and the payer misapplied it.

What CO-170 Means and How CMS Applies It

The official X12 description is: "Payment is denied when performed/billed by this type of provider." Its sibling, CARC 171, adds the facility dimension: "Payment is denied when performed/billed by this type of provider in this type of facility."

CMS writes CO-170 into specific coverage instructions in the Medicare Claims Processing Manual:

Annual depression screening (G0444). Chapter 18, section 190.7, denies G0444 "submitted on a TOB other than 13X, 71X, 77X, and 85X" with CARC 170 and RARC N428. Section 190.6 lists those as outpatient hospital (13X), rural health clinic (71X), federally qualified health center (77X) and critical access hospital (85X) bills.
Intensive behavioral therapy for cardiovascular disease (G0446). Chapter 18, section 160.3, denies institutional G0446 claims on other bill types with CARC 170 and N428.
Ambulatory surgical center billing. Chapter 14 denies HCPCS Q1003 "if billed by an entity other than a Medicare-approved ASC" with group code CO and CARC 170.

In the Chapter 18 instructions, the group is PR only when a signed ABN is on file (GA modifier) and CO when it is not.

Why CO-170 Happens

The service was billed on an institutional type of bill the coverage instruction does not include.
The billing entity is not the provider type the payer pays for that code, such as a non-ASC billing an ASC-only item.
A commercial or Medicaid policy restricts the code to specific provider categories, which the remark code or the 835 policy reference should identify.
The provider was enrolled or credentialed under a provider type that does not match the service.

How to Fix or Appeal a CO-170

Read the remark code and any policy reference on the 835 to learn whether the problem is setting, bill type or provider category.
Open the coverage rule and list the provider types and bill types it allows for the code.
If the service was furnished and documented under an allowed entity or bill type, correct the claim so it is billed that way, for example on the covered type of bill.
If your provider type is allowed and the payer misread its records, fix the enrollment or credentialing data and ask for reprocessing, or file a redetermination within 120 days for Medicare.
If no allowed route exists for your organization, write the amount off and stop scheduling that service under your current billing setup.
To contest a misapplied rule, draft the appeal in the appeal generator and cite the policy text.

CO-170 Compared With CO-171, CO-185, CO-8 and CO-58

CO-171 narrows CO-170 to a provider type in a particular kind of facility. CO-185 is about the individual rendering clinician not being eligible for the service, while CO-170 is about the provider or billing category. CO-8 means the procedure code is inconsistent with the provider type or specialty taxonomy. CO-58 concerns an invalid or inappropriate place of service. CO-96 is a general non-covered charge, and CO-109 means the claim went to the wrong payer or contractor altogether.

Frequently Asked Questions

What is the difference between CO-170 and CO-185?

CO-170 says payment is denied when the service is performed or billed by this type of provider, a category or bill-type rule. CO-185 says the specific rendering provider is not eligible to perform the service. Check the billing entity and bill type for CO-170, and the clinician's enrollment and licensure for CO-185.

What is the difference between CO-170 and CO-171?

Both deny payment based on provider type. CO-171 adds a facility condition: the provider type is not paid for the service in that type of facility. Look at where the service was performed when you see CO-171.

Can I bill the patient for a CO-170 denial?

Not under the CO group, which marks the denial as the provider's responsibility. Medicare's preventive-service instructions that use CARC 170 assign it to the patient only when a signed ABN is on file and the GA modifier was used.

Is CO-170 appealable?

Yes, but appeals succeed only when the policy already covers your provider or bill type and the payer applied it wrongly. If the claim simply went out on the wrong bill type, a corrected claim is faster than an appeal. Medicare redeterminations are due within 120 days of receiving the initial determination.

Informational only, not legal, medical, or billing advice. Always verify against your current payer contract and policy.

Reroute or appeal a CO-170

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