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CO-58 Denial Code: Inappropriate Place of Service

CO-58 means the payer judged the place where treatment was rendered to be inappropriate or invalid for the service. Either the place of service code on the claim is wrong, or the payer believes the service should have been provided in a different setting.

Quick facts

Code
CO-58 (CARC 58)
Status
Active In use since January 1, 1995; last modified July 1, 2017.
Code set
Claim Adjustment Reason Codes (CARC)
Group codes
  • CO (Contractual Obligation): The usual group. The provider absorbs the amount unless the claim is corrected or the denial is overturned.
  • PR (Patient Responsibility): Sometimes used when the patient chose a setting the plan doesn't cover and accepted responsibility. Confirm before billing.
Official description
Treatment was deemed by the payer to have been rendered in an inappropriate or invalid place of service. 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-58 means

CARC 58 says treatment was deemed by the payer to have been rendered in an inappropriate or invalid place of service. The payer isn’t only checking whether codes are compatible, as with CO-5. It’s saying that the setting, as reported in box 24B or on the institutional claim, wasn’t appropriate or valid for this treatment.

Two kinds of situations lead here. In the first, the POS code is simply wrong or invalid, for example a deleted or nonexistent code or a code for a setting the provider doesn’t operate in. In the second, the POS is accurate but the payer’s site-of-service policy says the service should be delivered somewhere else, such as an ambulatory surgery center instead of a hospital outpatient department.

The usage note refers to the 835 Healthcare Policy Identification segment for the payer’s policy.

Common causes

  • Invalid or outdated POS code on the claim.
  • Default POS from the practice management system that doesn’t match the location.
  • Site-of-service policies that limit certain procedures or infusions to lower-cost settings.
  • Telehealth POS used where the payer doesn’t allow telehealth for the service.
  • Home or residential settings not recognized by the payer for this service.

How to fix it

  1. Confirm the actual setting from the documentation and facility records.
  2. Check the POS code against the current POS code set and the payer’s accepted codes.
  3. Correct box 24B (and the service facility in box 32 and 32a if needed), then send a corrected claim with resubmission code 7 in box 22.
  4. If the setting was right, review the payer’s site-of-service policy and appeal with clinical reasons the setting was needed, such as comorbidities or safety concerns.
  5. Don’t bill the patient under CO.

How to prevent it

  • Map each location to its correct POS in your billing system.
  • Check site-of-service policies before scheduling procedures or infusions, and request authorization for exceptions.
  • Keep telehealth rules by payer current.
  • Validate POS before submission. A Claims Validator can flag invalid or unusual POS codes.

Specialty notes

Infusion centers, surgical specialties, and imaging centers are most affected by payer site-of-service programs. Behavioral health practices see CO-58 mainly with telehealth POS choices.

Remark codes that may appear with CO-58

  • M77 (Missing/incomplete/invalid/inappropriate place of service.): The place of service is missing, incomplete, invalid, or inappropriate.
  • MA114 (Missing/incomplete/invalid information on where the services were furnished.): Information on where services were furnished is missing or invalid.
  • CO-5 (The procedure code/type of bill is inconsistent with the place of service.): The procedure code is inconsistent with the POS, a coding-level edit.
  • CO-171 (Payment is denied when performed/billed by this type of provider in this type of facility.): Denied when performed by this type of provider in this type of facility.
  • CO-50 (These are non-covered services because this is not deemed a 'medical necessity' by the payer.): Not medically necessary, which may apply when the payer questions a higher-cost setting.
  • CO-40 (Charges do not meet qualifications for emergent/urgent care.): Doesn't meet emergency or urgent care criteria.

CO-58 FAQ

What's the difference between CO-5 and CO-58?

CO-5 is usually an automated edit that finds the procedure code and POS incompatible. CO-58 reflects the payer's judgment that the setting itself was inappropriate or invalid, which may involve a coverage policy or review.

How do I fix CO-58?

Confirm where the service actually took place and correct box 24B if it was wrong. If it was right, review the payer's site-of-service policy and appeal with documentation of why that setting was needed.

Do site-of-service policies apply to outpatient procedures?

Some payers have policies that steer certain procedures or infusions to lower-cost settings, such as ambulatory surgery centers or home infusion, unless clinical reasons require a hospital setting. Check the payer's policy for the service.