CO-29: The time limit for filing has expired.
The claim was submitted after the payer's timely filing deadline, so it is denied outright regardless of whether the service was otherwise payable.
What the group code means
- CO
- Contractual Obligation. The provider is responsible and the amount cannot be billed to the patient.
Why it fires
- The claim was submitted after the payer's contractual or regulatory filing deadline, often 90 days to one year from the date of service
- The original claim was filed on time but a corrected or resubmitted claim missed the deadline for corrections
- A delay in receiving eligibility, authorization, or coordination of benefits information pushed submission past the deadline
Corrective actions, ranked
- 1
Check the actual filing date
Pull clearinghouse or EDI acceptance reports to prove the original claim was received within the deadline. A payer system delay is different from a late submission.
- 2
Document a good cause exception
If the delay was caused by the payer, such as a late eligibility response or retroactive enrollment, gather proof for a timely filing appeal.
- 3
Fix the internal workflow
If this is a recurring pattern, shorten the internal cycle time from charge entry to claim submission.
Is it worth appealing
Appeal aggressively when you have proof of timely original submission, such as a clearinghouse acceptance report, or a documented good cause exception like retroactive eligibility.
Retrieved 2026-07-18.
Do not let this happen again
Scrub the claim against NCCI PTP and MUE edits before you submit, free and in your browser.
DenialPath provides billing and administrative guidance based on published CMS and X12 sources. It is not medical advice, not a coverage determination, and not a guarantee of payment. NCCI and MUE edits are republished quarterly and payer policies vary by contract. Always confirm against the payer's own current policy before submitting or appealing.