> ## Documentation Index
> Fetch the complete documentation index at: https://mso.getlemma.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Timely filing limits by payer
> How filing limits are set, the ones fixed by regulation, what to record per contract, and the evidence that wins a CARC 29 appeal.
**Timely filing** is the deadline by which a claim must reach the payer. Miss it and the claim is generally unpayable, CARC 29, with no clinical or coding defect involved.
**Your contract governs, not this page.**
Commercial timely filing limits are **contractual**, and they vary by payer, by product line, and by individual negotiated agreement. Two practices can have different limits with the same payer.
Publishing a table of "commercial payer X = N days" would be wrong for a meaningful share of readers, and a wrong deadline is worse than no deadline. **Record each limit from your own executed contract**, into your enrollment grid, when you sign.
What follows is what is fixed by regulation, the typical ranges, and how to work the problem.
## Fixed by regulation
| Payer | Initial filing limit | Basis |
| ---------------------------- | -------------------------------------------------------- | ------------------------------------ |
| **Medicare fee-for-service** | **12 months from the date of service** | Statutory and regulatory1 |
| Medicare Advantage | Set by the plan's contract, **not** Medicare's 12 months | Plan contract |
| Medicaid | State-specific; commonly 90 days to 12 months | State regulation |
| TRICARE | Set by program rules | Program |
| Workers' compensation | State-specific | State regulation |
**Medicare Advantage plans are not bound by Medicare's 12-month limit.** Practices routinely assume they are and lose claims. MA plans set their filing limits by contract, and they are frequently far shorter.
## Typical commercial ranges
Directional only, **confirm each from your own contract**.
| Product type | Commonly seen |
| ---------------------- | --------------------------------------------------------------------------- |
| Commercial PPO/HMO | 90 to 180 days |
| Some national carriers | Up to 12 months on some products |
| Medicaid MCO | Frequently short, sometimes 90 days |
| Secondary / COB claims | Often measured from the **primary's remittance date**, not the service date |
## The three windows to record
Each payer has **three** deadlines, and they differ:
| Window | What it governs | Typical relationship |
| ------------------- | ------------------------------------ | ------------------------------------------------------- |
| **Initial filing** | Original claim submission | The longest |
| **Corrected claim** | Resubmitting a claim with fixed data | Often **shorter** than initial |
| **Appeal** | Contesting an adjudication | Runs from the **remittance date**, not the service date |
Record all three per payer when you sign the contract.
## Proving you filed on time
**Clearinghouse acceptance reports are the standard evidence.** A 277CA showing payer acceptance on a specific date, or a clearinghouse transmission report, is what wins a CARC 29 appeal.
A screenshot of your PM system showing "submitted" is **not** evidence — it proves you pressed a button, not that the payer received anything.
Retain acceptance reports for at least the longest appeal window across your payer mix.
## The exceptions
| Exception | Basis |
| ---------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------- |
| **Proof of timely submission** | The claim was filed on time; the payer lost or misprocessed it. Strongest argument. |
| **Retroactive eligibility** | Coverage backdated after service; the clock generally runs from when eligibility was established |
| **Coordination of benefits delay** | The secondary's clock typically runs from the primary's remittance |
| **Payer error** | The claim was rejected in error and promptly resubmitted |
| **Provider enrollment delay** | Where a retro-effective date was granted, ask how the payer measures filing from it |
| **Catastrophic circumstances** | Disaster or systems outage. The **2024 Change Healthcare outage** produced widespread accommodations, a useful precedent if it recurs. |
Each has a documentation requirement. Assemble it with the appeal.
## The guardrails that get write-offs to zero
The clock starts at the date of service.
**The most common cause of a timely-filing loss is a claim stuck in a rejection loop.** A 277CA rejection means nothing was filed as far as the payer is concerned, while your system shows it as "submitted." A rejected claim sitting for two months has consumed two months of a 90-day window.
Every claim submitted more than three days ago with no 277CA acceptance. This catches claims lost between your system and the payer, the failure nothing else surfaces.
Claims held during credentialing, awaiting authorization, or pending COB need an aging report with the deadline attached.
If the limit is 90 days, escalate anything unfiled at 45. The buffer absorbs the rejection loop.
Weekly, by payer.
Any non-zero number gets a root cause and a process change.
## The grid template
| Field |
| ---------------------------------------------- |
| Entity |
| Payer, and product line |
| **Initial filing limit** |
| **Corrected claim window** |
| **Appeal window** (and from what date it runs) |
| Contract effective date |
| Where the limit is stated in the contract |
| Date recorded / verified |
Verify annually and on every contract renewal or amendment — unilateral amendment clauses mean a limit can change without your signature.
## Sources
1. Medicare timely filing: Social Security Act § 1842(b)(3)(B); 42 C.F.R. § 424.44. See CMS, [Medicare Claims Processing Manual](https://www.cms.gov/regulations-and-guidance/guidance/manuals/internet-only-manuals-ioms-items/cms018912), ch. 1. Confirm current rules and any exception provisions with CMS.
## Related topics
- [Beat timely filing limits](/guides/billing/beat-timely-filing.md)
- [File appeals](/guides/billing/file-appeals.md)
- [Enroll and contract with commercial payers](/guides/enrollment/enroll-with-commercial-payers.md)
- [Claim denials, explained](/concepts/payments/claim-denials.md)
- [Underpayments, fee schedules, and payer contracts](/concepts/payments/underpayments-and-contracts.md)
- [CARC codes (Claim Adjustment Reason Codes)](/reference/edi/carc-codes.md)
- [Payer enrollment & submission links](/reference/payers/enrollment-links.md)