How do I fix or resolve code CO-27?

Verify the patient's coverage termination date via a 270/271 eligibility transaction or the payer portal and compare it to the date of service on the claim. If the coverage termination date in the payer's system is incorrect (e.g., the patient's coverage was extended but the system shows an earlier termination), contact the payer to correct the enrollment record and resubmit the claim. If the coverage was genuinely terminated before the date of service, determine whether the patient has new coverage from another payer and submit the claim to that payer. If the patient has COBRA or continuation coverage, verify the COBRA premium payment status and resubmit the claim with COBRA documentation. If the patient has no current coverage, bill the patient directly or offer financial assistance/charity care options.

CO-27Denial CodeContractual Obligation

Code CO-27

Problem Description

Expenses incurred after coverage terminated.

Root Cause

The expenses or services were incurred after the patient's coverage terminated. The payer's eligibility system compares the date of service on the claim to the patient's coverage termination date and denies the claim if the service was rendered after the coverage ended. This commonly occurs when a patient loses coverage due to job change, plan cancellation, or aging out of a dependent plan, but continues to receive services using the old insurance card. The claim is denied as a contractual obligation — the payer is not responsible for services rendered after the coverage period ended.

Resolution Steps

1Verify the patient's coverage termination date via a 270/271 eligibility transaction or the payer portal and compare it to the date of service on the claim.
2If the coverage termination date in the payer's system is incorrect (e.g., the patient's coverage was extended but the system shows an earlier termination), contact the payer to correct the enrollment record and resubmit the claim.
3If the coverage was genuinely terminated before the date of service, determine whether the patient has new coverage from another payer and submit the claim to that payer.
4If the patient has COBRA or continuation coverage, verify the COBRA premium payment status and resubmit the claim with COBRA documentation.
5If the patient has no current coverage, bill the patient directly or offer financial assistance/charity care options.

EHR Documentation Note

Claim denied CO-27 — expenses incurred after coverage terminated; verified termination date, identified new coverage or COBRA, or billed patient directly.

Preventative Action

Verify active coverage status at every visit via real-time eligibility checks and inform patients of coverage termination before rendering non-emergency services.

Related Codes in Contractual Obligation

CO-4

The procedure code is inconsistent with the modifier used. Usage: Refer to the 835 Healthcare Policy Identification Segment (loop 2110 Service Payment Information REF), if present.

CO-5

The procedure code/type of bill is inconsistent with the place of service. Usage: Refer to the 835 Healthcare Policy Identification Segment (loop 2110 Service Payment Information REF), if present.

CO-16

Claim/service lacks information or has submission/billing error(s). Usage: Do not use this code for claims attachment(s)/other documentation. At least one Remark Code must be provided (may be comprised of either the NCPDP Reject Reason Code, or Remittance Advice Remark Code that is not an ALERT.) Refer to the 835 Healthcare Policy Identification Segment (loop 2110 Service Payment Information REF), if present.

CO-18

Exact duplicate claim/service (Use only with Group Code OA except where state workers' compensation regulations requires CO)

This directory provides reference information only and does not constitute official legal, medical, or financial billing advice. Always consult the payer's official remittance advice and current coding guidelines.