CO-26: Expenses Incurred Prior to Coverage
CO (Contractual Obligation)What is CO-26?
CO-26 is a Contractual Obligation code indicating the service was rendered before the patient's coverage effective date. The patient was not yet covered by the plan at the time of service.
Why Does CO-26 Occur?
- Service date is before the patient's coverage start date.
- Coverage was terminated before the date of service but the termination was not updated in the billing system.
- Retroactive enrollment has not been processed by the payer yet.
How to Fix CO-26 Denials
- Verify the patient's coverage effective date on the payer portal or through a 270/271 eligibility check.
- If the patient was not covered, bill the patient directly or identify the correct payer.
- If the patient has retroactive enrollment pending, hold the claim and resubmit after the enrollment processes.
- Appeal with documentation of coverage if the payer's records are incorrect.
CO-26 by Payer
| Payer | Common RARC | Appeal Deadline | Notes |
|---|---|---|---|
| UnitedHealthcare | Varies | 60 days from remittance | Reconsideration required before formal appeal. |
| Anthem | Varies | 365 days from denial notice | Check state-specific provider manual for variations. |
| Aetna | Varies | 180 days from denial | Strict in-network filing enforcement. |
| Cigna | Varies | 180 days from denial | Cigna COB team: 1-800-244-6224. |
| Medicare | Varies | 120 days (redetermination at MAC) | Five levels of appeal starting with MAC redetermination. |
Related CARC Codes
If you are seeing CO-26, check these related codes: CO-44 (subscriber not eligible), CO-27 (coverage terminated), CO-26 (prior to coverage).
Common Questions About CO-26
What does CO-26 mean?
CO-26 indicates expenses incurred prior to coverage. Check the RARC code on the EOB for the specific reason and follow the resolution steps above.
Can I appeal a CO-26 denial?
Yes. Commercial payers allow 60-365 days to appeal depending on the payer. Gather supporting documentation before filing. Medicare allows 120 days for a redetermination request.
Altair catches CO-26 denials before submission with eligibility verification. See how pre-submit claim scoring works.