CO-29 (Time Limit for Filing Expired)
Contractual Obligation 29 — the time limit for filing has expired.
1 min read · Last reviewed May 23, 2026
At a glance
- Category
- Denials & Appeals
- Primary sources
- 1
- Workspace handoff
- denial workbench →
Where this comes up
This is denial-workbench territory. A remit posts with a CARC/RARC, the biller decides whether to rebill, appeal, or write off, and the appeal packet has to cite the chart, the order, and the payer's own policy language. Recurring patterns trace back to an upstream workflow gap.
Full definition
What it is in practice
Each payer has its own timely filing limit (Medicare = 12 months; commercial varies 90 days to 1 year). After the window, claims are not paid.
How it shows up in your practice
Track aging by payer. The metric you care about is "claims filed within 30 days of DOS." Late filings produce CO-29 denials that are difficult to appeal.
Sources
- CMS — CARChttps://x12.org/codes/claim-adjustment-reason-codes
Resolve CO-29 timely-filing denials in the Denial Workbench
Open denial workbench →Related terms
- Denials & AppealsTimely FilingThe payer's deadline for receiving an initial claim, after which the claim is denied as untimely.
- Denials & AppealsCARC (Claim Adjustment Reason Code)X12-maintained codes communicating why a claim or service line was paid differently than billed.
- Denials & AppealsDenial ManagementThe end-to-end workflow of identifying, categorizing, appealing, and preventing claim denials.
D3rx is a healthcare-billing and compliance research aid maintained by D3rx Inc. Articles are drafted by an LLM (Anthropic Claude) against primary HHS, OCR, CMS, eCFR, NIST, and state-regulator publications, and reviewed for restraint and source fidelity by the D3rx team.
Reviewer status: a named credentialed reviewer (CHC, CHPC, or healthcare attorney) is being engaged. Until that engagement is finalized, this page does not claim credentialed review.
Related across the archive
- GlossaryCARC (Claim Adjustment Reason Code)X12-maintained codes communicating why a claim or service line was paid differently than billed.
- GlossaryDenial ManagementThe end-to-end workflow of identifying, categorizing, appealing, and preventing claim denials.
- GlossaryTimely FilingThe payer's deadline for receiving an initial claim, after which the claim is denied as untimely.
- GlossaryAppeal LetterThe written request to a payer to reconsider a denied or partially-paid claim.
- GlossaryCO-109 (Claim Not Covered by Payer)Contractual Obligation 109 — the claim is not covered by this payer/contractor.
- GlossaryCO-16 (Claim Lacks Information)Contractual Obligation 16 — the claim or service line lacks information or has submission/billing errors.
- GlossaryCO-18 (Duplicate Claim)Contractual Obligation 18 — exact duplicate of another claim.
- BillingHow to Appeal an Insurance Denial: Step-by-Step GuideClaim denied? Step-by-step appeal process with payer deadlines, denial code fixes, appeal letter template, and escalation options.
This glossary entry is a research aid for billing and compliance staff. It does not provide legal, medical, or financial advice and does not replace counsel. References cited link to primary sources at HHS, OCR, CMS, eCFR, NIST, and the relevant payer or industry body.