Official CARC description: “The time limit for filing has expired.” Here’s what it actually means, why it fires, and how to get the claim paid.
The claim arrived after the payer's filing deadline (90–365 days depending on contract). The write-off is NOT automatic — proof of timely original submission wins these routinely.
Liability group: CO = Contractual Obligation — the provider absorbs it — the amount cannot be billed to the patient. If the denial is wrong, the money is recovered by correcting or appealing the claim, not by balance-billing.
Also written: CO-29, CO29, “denial code 29”, “29 denial code” or “reason code 29” — same CARC, different ERA formatting.
Pull the clearinghouse acceptance report for the ORIGINAL submission date
Check the contract's actual filing limit — payer reps often quote the wrong one
For COB delays: most contracts start the clock at the primary EOB date
Set a weekly rejected-claims sweep so rejections never age out silently
Appeal with proof of timely filing: clearinghouse acceptance report, ANSI 277CA, certified-mail receipt, or the primary EOB date for secondaries. Most payers must accept electronic acceptance reports as proof.
Fill in the denial facts — use placeholders, never real patient data (the letter keeps [PATIENT NAME]-style fields so you can merge real details privately). A payer-ready draft with an enclosure checklist comes back in ~20 seconds.
Your appeal letter draft will appear here.
The official CARC description for CO 29 is: “The time limit for filing has expired.” In practice: The claim arrived after the payer's filing deadline (90–365 days depending on contract). The write-off is NOT automatic — proof of timely original submission wins these routinely.
Denial code 29 under the CO group (Contractual Obligation) means: The time limit for filing has expired. The number is the reason; the CO prefix decides who is liable — the provider absorbs it — the amount cannot be billed to the patient. If the denial is wrong, the money is recovered by correcting or appealing the claim, not by balance-billing.
Yes. CO 29, CO-29, CO29 and “denial code 29” are the same CARC — clearinghouses, payer portals and PM systems just print it differently. Only the group prefix (CO, PR, OA or PI) changes the meaning, because it changes who has to absorb the amount.
CO stands for Contractual Obligation — the provider absorbs it — the amount cannot be billed to the patient. If the denial is wrong, the money is recovered by correcting or appealing the claim, not by balance-billing.
Appeal with proof of timely filing: clearinghouse acceptance report, ANSI 277CA, certified-mail receipt, or the primary EOB date for secondaries. Most payers must accept electronic acceptance reports as proof.