CO-29 — Timely filing limit expired
Also seen as: CO-29, PR-29
What it means
The claim arrived after the payer's timely-filing window (often 90-365 days from the date of service). Many payers allow an appeal with proof the claim was sent on time.
Standard definition (paraphrased): The claim was received after the payer's filing deadline.
Why it happens
- • The claim was submitted after the deadline
- • An earlier submission was lost and the resend fell outside the window
- • The window for OON claims is shorter than assumed
Common next steps therapists take
- • Check the payer's timely-filing window and whether an exception process exists
- • Gather any proof of an earlier on-time submission
- • Many practices file a timely-filing appeal with that proof
A blank appeal-letter template is available for this kind of denial — Timely-filing appeal.
Educational information only
This page is general educational information, not legal, billing, or medical advice, and not a determination about any specific claim. Denial codes are maintained by the X12 committee and updated periodically. Always verify code meanings, benefits, and requirements directly with the payer and against your own records.
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