CO-26: Expenses Incurred Prior to Coverage

What Does CO-26 Mean?

With CO (Contractual Obligation), the CARC 26 adjustment is the provider's responsibility. The payer denied or reduced payment because of the date of service on the claim is before the patient's insurance coverage began. The patient is not liable for this amount. If the denial is in error, the provider can correct and resubmit the claim or file an appeal with supporting documentation.

CARC 26 indicates expenses incurred prior to coverage. The payer determined that the service or a portion of it does not meet coverage criteria under the patient's current plan benefits or the applicable coverage rules.

Common scenarios that trigger this adjustment include: the date of service on the claim is before the patient's insurance coverage began; The patient's coverage was retroactively terminated to a date before the service; The payer has an incorrect coverage start date in their system. The group code paired with CARC 26 determines who bears the financial responsibility — CO places it on the provider as a contractual obligation, PR shifts it to the patient, OA indicates a coordination of benefits or other payer adjustment.

Common Causes

How to Resolve

1. Review the remittance details Examine the CO-26 adjustment and any accompanying RARC codes to identify the specific reason for the denial.
2. Identify the root cause Determine which issue applies: service date before coverage effective date, retroactive coverage termination, incorrect coverage effective date on file.
3. Correct the claim Address the identified issue — update the claim data in your billing system to resolve the expenses incurred prior to coverage problem.
4. Resubmit the corrected claim Submit the corrected claim following the payer's resubmission guidelines. Include any supporting documentation that addresses the denial reason.
5. Appeal if the original claim was correct If the payer has an incorrect coverage effective date, appeal with enrollment documentation, the insurance card showing the effective date, or confirmation from the employer/marketplace.

Common RARC Pairings

The RARC code tells you exactly what triggered the CO-26:

How to Prevent CO-26

• Verify insurance eligibility and coverage dates before providing services
• Check coverage effective date during patient registration
• Use real-time eligibility verification tools
• Confirm coverage for new patients before their first visit

Also Filed As

The same CARC 26 may appear with different Group Codes:

Related Denial Codes