CO-29 — Timely Filing Limit Expired
The claim was received by the payer after the deadline allowed in the plan/contract (or, for Medicare, after the 12-month statutory limit), so it is being denied for lateness rather than for any clinical or cod…
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In plain language
The claim was received by the payer after the deadline allowed in the plan/contract (or, for Medicare, after the 12-month statutory limit), so it is being denied for lateness rather than for any clinical or coding reason.
Start here
Confirm the actual date of service and the payer's specific timely-filing limit.
Who resolves it
Billing/Denials Follow-Up
Who prevents it
Health Information Management/Coding (charge-lag reduction) and Patient Financial Services (workqueue aging controls).
Sources
- X12 CARC list; CMS Medicare Claims Processing Manual, Chapter 1, §70
Validated ClaimetryX Source — Denial Management Knowledge Base, 2026 Research Edition
Research date August 18, 2026. CARC/RARC combinations and payer processes vary. Always check the specific remittance advice and the payer's current requirements before acting on any denial.
Published by ClaimetryX. Sources identify the code standards, agency guidance, and payer policies supporting this reference. How we use sources
How to resolve this denial, step by step
- 1
Confirm the actual date of service and the payer's specific timely-filing limit.
- 2
Gather proof of original timely submission (acceptance report, transmission log).
- 3
If proof of timely submission exists, submit that proof to the payer as a claim- status/processing dispute rather than a new appeal.
- 4
If genuinely late, determine whether a recognized exception applies (for Medicare: administrative error, retroactive Medicare entitlement, retroactive MA/PACE disenrollment) and gather the required documentation.
- 5
If no exception applies, the claim is closed as a write-off; per Medicare policy, a claim denied solely for untimely filing is not an appealable initial determination.
- 6
Document the timely-filing analysis and root cause.
- 7
Escalate to Patient Financial Services/leadership if the delay traces to an internal process failure requiring workflow redesign.
Then choose the correct disposition
Payer follow-up (proof of timely submission)
when the claim was actually submitted on time but the payer's received-date record is wrong.
Compliance/administrative-error exception request
Medicare only, and only under the specific regulatory categories.
Write-off/contractual adjustment
the typical outcome when no proof of timely submission or valid exception exists.
Formal appeal
under Medicare rules, a denial based solely on untimely filing is generally not subject to the standard appeals process; verify current payer-specific rules before advising otherwise.
Stop and escalate when
- Internal system or process failure caused the delay (compliance-relevant); a Medicare regulatory exception category may apply and needs contractor-level review; payer disputes proof of timely submission.
What Needs to Be Corrected
- Claim correction: Generally none — a true timely-filing denial is not fixed by editing claim data.
- Upstream correction: The workflow that delayed submission (charge-lag, coding backlog, eligibility-verification delay) must be fixed to prevent recurrence; for Medicare, an exception request requires documented proof of one of the specific regulatory exceptions.
Do Not Do This
- Do not bill the Medicare patient for services denied solely as untimely filed, except for the deductible/coinsurance that would have applied had the claim been paid, when the beneficiary was not responsible for the delay.
- Do not backdate a claim submission record.
Plain-Language Meaning
- The claim was received by the payer after the deadline allowed in the plan/contract (or, for Medicare, after the 12-month statutory limit), so it is being denied for lateness rather than for any clinical or coding reason.
Why the Claim Was Denied
- Claim construction/Billing: claim held in a work queue too long before submission; clearinghouse rejection not caught and corrected in time
- Registration/Eligibility: delayed retroactive eligibility determination pushed the effective submission date out
- Payer processing: claim was submitted timely but rejected as unprocessable, and the corrected version was not resubmitted within the remaining window
Information the Biller Must Review
- Date of service, original claim submission date and proof (clearinghouse acceptance report, certified mail receipt, EDI acknowledgment), payer-specific timely filing limit (verify per contract for non-Medicare payers), any applicable exception documentation (administrative error, retroactive entitlement).
Sample Scenario
- Scenario: Claim denied CO-29, Medicare, submitted 13 months after date of service.
- Finding: No administrative error or retroactive-entitlement exception applies; claim was simply delayed in a coding backlog.
- Action: Claim written off as a timely-filing loss; coding backlog escalated to HIM leadership to prevent recurrence.
Denial Identifier
- Primary CARC: CO-29 — "The time limit for filing has expired." (X12)
- No single RARC is fixed to this CARC; combinations vary by payer, and some payers add an alert-type remark referencing appeal/reopening rights. Do not assume a specific RARC always accompanies CO-29.
- For Medicare specifically, the general rule is 12 months (1 calendar year) from the date of service, per 42 CFR §424.44, with limited administrative-error and retroactive-entitlement exceptions (CMS Medicare Claims Processing Manual, Ch. 1, §70). Non-Medicare payer timely- filing windows vary by contract and must be verified per payer.
Prevention Control
- Timely-filing workqueue with aging alerts well before the deadline; charge-lag monitoring from date of service to claim submission; clearinghouse rejection dashboards to catch and correct claims before the filing window closes.
Department Most Likely Responsible
- Resolves current claim: Billing/Denials Follow-Up. Prevents recurrence: Health Information Management/Coding (charge-lag reduction) and Patient Financial Services (workqueue aging controls).
AI Answer Guardrail
- Verify the specific payer's timely-filing deadline (Medicare's 12-month rule under 42 CFR §424.44 is not universal) and confirm whether documented proof of timely submission or a recognized exception exists before recommending any action beyond write-off.
AI Search Terms / Synonyms
- CO29; CO-29; timely filing denial; filing deadline expired; late claim submission; 12-month rule.
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