Skip to main content

CO-95 Denial Code: Plan Procedures Not Followed

CO-95 means the payer denied or reduced the claim because a required plan procedure was not followed, for example a referral, notification, second opinion, or other administrative step. The remark code or payer policy usually identifies which procedure was missed.

Quick facts

Code
CO-95 (CARC 95)
Status
Active In use since January 1, 1995; last modified September 30, 2007.
Code set
Claim Adjustment Reason Codes (CARC)
Group codes
  • CO (Contractual Obligation): The provider is held responsible for the missed procedure. Under an in-network contract the amount generally cannot be billed to the patient.
  • PR (Patient Responsibility): The patient failed to follow a plan requirement they were responsible for, such as obtaining a referral themselves. The plan may allow the patient to be billed.
Official description
Plan procedures not followed.
X12 Claim Adjustment Reason Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What CO-95 means

CARC 95 is a broad code: plan procedures not followed. The payer is saying the service might have been payable, but a required administrative step in the plan or contract did not happen. Unlike more specific codes such as CO-197 (authorization absent) or CO-288 (referral absent), CARC 95 covers whatever procedure the plan defines.

Because it is general, the remark codes on the ERA and any policy reference in the 835 are essential. Without them you are guessing which step was missed.

Common causes

  • No referral on file from the primary care provider for an HMO or point-of-service plan.
  • A required notification (for example, an inpatient admission or a maternity notification) was not sent within the plan’s window.
  • A service was performed without the precertification the plan requires, and the payer used CARC 95 rather than 197.
  • The plan requires a designated lab, imaging center, or specialty pharmacy, and another was used.
  • A required second opinion, care management enrollment, or pre-service review did not take place.
  • The authorization or referral number was obtained but not reported in box 23 of the CMS-1500 or the equivalent 837 field.

How to fix it

  1. Read the remark code and policy reference to identify the missed procedure. If none is given, call provider services and ask for the specific requirement.
  2. If the step was done but not reported, send a corrected claim (resubmission code 7 in box 22, with the original claim number) that includes the authorization, referral, or notification number.
  3. If the step was done and reported, submit a reconsideration or appeal with proof: referral copy, fax confirmation, portal screenshot, or call reference.
  4. If the step was missed, check whether the payer allows retroactive authorization or notification. Some do for urgent or emergency situations. Follow the payer’s timeline.
  5. If none of this applies, under CO the amount is generally a write-off. Under PR, bill the patient only when plan terms support it.

How to prevent it

  • Build a payer requirements grid covering referrals, notifications, and designated vendors by plan type.
  • Verify requirements at scheduling, not at check-in, so there is time to obtain what is needed.
  • Store referral and authorization numbers in the patient account so they flow to box 23 automatically.
  • Track CO-95 by payer and service line. Repeat denials usually trace to a single missing step. Our guide on authorization and referral denials covers the workflow.

Specialty notes

Behavioral health and PT/OT often face visit-based notification requirements, where each episode must be registered with the plan or a delegated vendor. A missed registration can show up as CARC 95 even when medical necessity is not in question.

Remark codes that may appear with CO-95

  • N54 (Claim information is inconsistent with pre-certified/authorized services.): Points to a claim information inconsistency with pre-certified or authorized services, a common procedural miss.
  • M62 (Missing/incomplete/invalid treatment authorization code.): Missing or invalid treatment authorization code, one of the most common procedures not followed.
  • N130 (Consult plan benefit documents/guidelines for information about restrictions for this service.): Directs you to plan benefit documents for the specific requirement.
  • CO-197 (Precertification/authorization/notification/pre-treatment absent.): Specifically for missing precertification or authorization. More precise than CARC 95 when an auth was absent.
  • CO-288 (Referral absent): Specifically for an absent referral.
  • CO-61 (Adjusted for failure to obtain second surgical opinion): Reduction for failure to obtain a second surgical opinion, a specific plan procedure.
  • OA-136 (Failure to follow prior payer's coverage rules. (Use only with Group Code OA)): Failure to follow the prior payer's coverage rules, used on secondary claims.
  • CO-272 (Coverage/program guidelines were not met.): Coverage or program guidelines were not met.

CO-95 FAQ

What counts as a plan procedure under CO-95?

Administrative requirements in the patient's plan or your contract, such as referrals, notifications, precertification, second opinions, or using a designated vendor. The remark code and the payer's policy tell you which one applied.

Can I appeal a CO-95 denial?

Yes, if you can show the procedure was followed or was not required. Include evidence such as a referral number, notification confirmation, or the policy language.

Can I bill the patient for CO-95?

Not under CO. If the payer reports it as PR because the patient skipped a step they were responsible for, check the plan terms and any financial waiver the patient signed.