> ## Documentation Index
> Fetch the complete documentation index at: https://dso.getlemma.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Beat timely filing limits
> Know each dental contract's limit, prove submission with clearinghouse acceptance reports, use the recognized exceptions, and build guardrails that drive timely-filing write-offs to zero.
**Timely filing** is the deadline by which a claim must reach the payer. A claim received after that deadline is generally unpayable and may return CARC 29 even though the care and coding were proper. Track these losses separately and work toward eliminating them.
## Prerequisites
* Each payer's timely filing limit, recorded from the contract
* Clearinghouse acceptance reports retained
* A held-claims report
## Know your limits
Dental payers' limits are **contract-specific**. There is no industry standard, so record the deadline in each participation agreement.
| Payer type | Where the limit lives |
| --------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Commercial dental PPO** | Your participation agreement. Deadlines commonly range from 90 days to 12 months and vary by carrier and contract. |
| **Delta Dental** | Each member company's participation agreement. A multi-state group has a separate limit for each Delta company. |
| **Medicaid dental** | The dental benefit administrator's provider manual, within the state program's rules. These deadlines may be short. |
| **Leased-network claims** | The underlying contract whose fee schedule was applied, which may not be the payer named on the EOB |
| **Secondary / COB claims** | Often measured from the primary's remittance date |
| **Medicare crossover work** | 12 months from the date of service for a Part B or DMEPOS claim. See [Bill medical plans for dental work](/guides/billing/bill-medical-for-dental-work). |
Record each payer's deadline in your tracking grid when you sign the contract. Some contracts allow only 90 days, which can be shorter than a credentialing delay or appeal cycle. This deserves attention after an [acquisition](/guides/growth/acquire-a-dental-practice), when claims may be held while credentialing under the buyer's TIN is completed.
There are also separate, usually shorter, windows for **corrected claims** and **appeals**. Record all three per payer. See [Timely filing limits by payer](/reference/payers/timely-filing-limits).
## Prove you filed on time
Use clearinghouse acceptance reports as evidence. A 277CA showing that the payer accepted the claim on a specific date, or a clearinghouse report showing successful transmission, supports a timely-filing appeal. A PMS screenshot marked "submitted" shows only that someone initiated submission, not that the payer received the claim.
Retain acceptance reports for at least the longest appeal window across your payers.
## The recognized exceptions
Where the deadline can be extended or excused:
| Exception | How it works |
| ---------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| **Proof of timely submission** | The claim was filed on time; the payer lost or misprocessed it. Strongest argument. |
| **Retroactive eligibility** | Coverage was backdated after the service, a situation that occurs in Medicaid. The filing period may run from when eligibility was established; verify the program rule. |
| **Coordination of benefits delay** | The secondary's clock typically runs from the primary's remittance |
| **Payer error** | The claim was rejected in error and resubmitted promptly |
| **Provider enrollment delay** | Where a retro-effective date was granted; ask how the payer measures filing from it |
| **Catastrophic circumstances** | Payers sometimes grant relief after a disaster or systems outage. **The 2024 Change Healthcare outage led to widespread accommodations**, and the ADA publicized emergency relief for dental practices. Cite that precedent when relevant. |
Each has a documentation requirement. Assemble it with the appeal.
## The guardrails
Getting timely-filing write-offs to zero is a process problem, not a diligence problem.
The clock starts at the date of service, not at charge entry. Every day of lag is a day of the window consumed.
Rejection loops are a common source of timely-filing losses. A 277CA rejection means the claim was never accepted. A rejected claim left unworked for two months has used two months of a 90-day window even if the PMS displays "submitted." A claim parked while waiting for an x-ray is also not filed, so send required attachments with the initial claim.
List every claim submitted more than three days ago with no 277CA acceptance. This report identifies claims that left your system but never reached the payer's accepted-claim inventory.
Claims held during credentialing, awaiting a required preauthorization, or pending COB resolution need an aging report with the deadline attached. See [Handle credentialing delays](/guides/enrollment/handle-credentialing-delays).
If the limit is 90 days, escalate anything unfiled at 45. The buffer absorbs the rejection loop.
A daily or weekly report of unfiled claims within 30 days of their limit, by payer.
Target zero. Any non-zero number gets a root cause and a process change.
## Appealing a CARC 29
Clearinghouse acceptance report, 277CA, or transmission confirmation showing the original submission date.
State the original submission date, attach the acceptance report, cite the contract's filing limit, and show the submission fell within it.
Retroactive eligibility, COB delay, payer error, or a retro-effective enrollment date.
And fix the process that caused it. A timely-filing write-off with no process change will recur.
## Verify it worked
* [ ] Every payer's initial, corrected-claim, and appeal windows recorded, including separate entries for each Delta member company and Medicaid dental benefit administrator
* [ ] Charges entered within one business day
* [ ] Rejections worked same-day
* [ ] Attachments ride with the claim, not after it
* [ ] Weekly no-acceptance report running
* [ ] Held claims tracked with deadlines
* [ ] Internal deadline set inside the contractual one
* [ ] Approaching-deadline alerts configured
* [ ] Acceptance reports retained for the longest appeal window
* [ ] Timely-filing write-offs tracked, targeting zero
## Common failure modes
| Failure | Consequence |
| ----------------------------------------------------------- | ----------------------------------------- |
| Not knowing a payer's limit | Discovering it via CARC 29 |
| Claim stuck in a rejection loop | Window consumed while appearing submitted |
| Claim held for an attachment | Same result: nothing was filed |
| No no-acceptance report | Lost claims invisible |
| Charge entry lag | Window consumed before submission |
| Held claims untracked during post-acquisition credentialing | An entire month of production ages out |
| No acceptance reports retained | No proof; appeal fails |
| Writing off without a root cause | It happens again |