How to Appeal CO-29 Denial: Time limit for filing has expired
The claim was not submitted within the payer's timely filing deadline. This guide explains what it means, why it happens, and exactly how to build a winning appeal.
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What Does CO-29 Mean?
The claim was not submitted within the payer's timely filing deadline.
Commonly seen in:
Step-by-Step Appeal Guide for CO-29
- 1
Locate proof of the original claim submission: clearinghouse 277 report, fax confirmation, or portal receipt
- 2
Calculate the filing deadline from the date of service (or primary EOB date for COB claims)
- 3
Document any payer-caused delays that prevented timely filing
- 4
Write a cover letter explaining the timeline and attaching all proof of timely filing
- 5
Submit the appeal before the payer's appeal deadline (typically 180 days from denial)
Counter-Arguments to Use in Your Appeal
These are the strongest arguments medical billing professionals use to overturn CO-29 denials.
Document the original submission date with proof (clearinghouse report, fax confirmation)
If delayed due to other payer processing, provide the primary EOB date and calculate from that
Cite state prompt-pay laws that extend filing deadlines in specific circumstances
If the payer caused the delay (wrong information, system issues), document the payer error
Regulations and Guidelines to Cite
Citing specific regulations strengthens your appeal and demonstrates you know your rights.
Expert Tip for CO-29 Appeals
Always keep proof of original submission. Clearinghouse 277 reports are your best evidence of timely filing.
Frequently Asked Questions
What is a CO-29 denial code?
The claim was not submitted within the payer's timely filing deadline.
Can I appeal a CO-29 denial?
Yes. All insurance denials are appealable. Timely filing denials require proof of original submission. Follow the step-by-step guide above and submit your appeal before the payer's deadline, typically 180 days from the denial date.
What documentation do I need to appeal CO-29?
For a CO-29 denial, you typically need: the original denial letter/EOB, clinical documentation supporting the service, any prior authorization records, and a cover letter citing the relevant regulations listed above. The specific documents depend on why the denial was issued.
How long does a CO-29 appeal take?
Most payers are required to process standard appeals within 30–60 days. Expedited appeals (for urgent care) must be decided within 72 hours. Under ERISA, group health plans must provide an appeal decision within 60 days for pre-service and 60 days for post-service claims.
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