You treat a patient, submit a claim, and wait for payment. Then the denial arrives: CO-29 Timely filing limit has expired. The service was medically necessary. The coding was perfect. But none of it matters, because you missed the deadline by a single day.
Timely filing limits are among the most unforgiving rules in medical billing. Unlike a coding error that can be corrected, an untimely filing denial is usually permanent. The payer keeps the money, and your practice writes off the entire charge.
In this guide, you will learn exactly what timely filing limits are, the specific deadlines for Medicare, Medicaid, and major commercial insurers, how to avoid common mistakes, and the rare exceptions that can save a late claim.
What Is a Timely Filing Limit?
A timely filing limit (TFL) is the strict deadline a payer sets for submitting a claim after a service is rendered. It is measured in days or months from the date of service. If a claim arrives even 24 hours late, it is denied as “untimely” with no appeal rights. For most small practices, this is the number one cause of preventable revenue loss.
Timely filing is not a suggestion. It is a hard contractual rule. Missing it means violating your payer agreement, which can harm relationships and lead to permanent write‑offs. For secondary or tertiary claims, the filing window typically begins on the date of primary payer determination, not the original date of service.
Timely Filing Limits by Payer (2026 Update)
Different payers enforce different deadlines. Below is a reference table for the most common payers. Warning: Out-of-network claims often have much shorter windows (e.g., 90 days) than in-network claims.
| Payer | Standard Filing Limit (From Date of Service) | Notes |
| Medicare (Original) | 365 days (12 months) | Applies to most Part A and Part B services. Extensions rare |
| Medicaid | 90 days to 365 days (state-dependent) | Texas: 95 days. Florida: 365 days. Check your state |
| UnitedHealthcare | 90 days | One of the tightest windows. Prioritize these claims weekly |
| Blue Cross Blue Shield | 90 to 180 days | Some local plans allow 365 days; many HMOs strictly 90 days |
| Aetna | 90 to 180 days | Verify your specific fee schedule and contract |
| Cigna | 90 to 180 days | Varies by plan and network status |
Medicaid State Variations at a Glance
Because each state runs its own Medicaid program, deadlines vary significantly:
- Shortest limits: New York (90 days), Massachusetts (90 days), Texas (95 days)
- Longest limits: Florida, Ohio, Washington, Virginia, Oregon (365 days)
- Most states: Fall between 120 180 days
- Managed Care Organizations (MCOs): Often impose stricter deadlines than state Medicaid programs
The Three Timely Filing Clocks You Must Track
Most providers watch only the “initial claim” clock. This is a mistake. There are actually three separate timers running on every patient encounter.
1. Initial Submission Clock
- Starts: Date of service (professional) or discharge date (facility)
- Ends: 90 to 365 days later (payer‑dependent)
- Risk: If missed, 100% write‑off
2. Corrected/Rejected Claim Clock
- Starts: Date of rejection or denial
- Ends: Often just 60 days
- Risk: You fix the error, but if you submit the correction too late, it is denied
3. Appeal Clock
- Starts: Date of denial (remittance date)
- Ends: 30 to 60 days
- Risk: Missing this window locks the denial in place permanently
Common Reasons Providers Miss Timely Filing Deadlines
Understanding why deadlines are missed is the first step toward prevention.
- Credentialing delays: Seeing patients before your NPI and taxonomy codes are active with the payer
- “Pending” claims: Claims that sit unresolved until the clock runs out
- Incomplete documentation: Delays in completing charts or obtaining medical records
- Missing patient information: Incomplete demographics or insurance details at registration
- Eligibility or coordination of benefit issues: Delays while verifying coverage or primary payer
- Missing prior authorization or referral numbers
- Clearinghouse rejections: Claims rejected at the clearinghouse level may never reach the payer, yet the clock continues to run. Monitor these rejections closely
How to Prevent Timely Filing Denials
Prevention is far more effective than chasing exceptions.
1. Submit Claims Within 48 Hours of Service
The sooner you submit, the less risk you face. Build a workflow that prioritizes claim submission immediately after coding is complete.
2. Track Payer Deadlines in a Centralized System
Create a reference sheet or use your practice management system to store timely filing limits for every payer you bill. Update it whenever contracts change.
3. Monitor Clearinghouse Rejections Daily
Rejected claims do not stop the timely filing clock. Assign a staff member to review clearinghouse reports each morning and correct rejections within 24 hours.
4. Verify Eligibility and Benefits Before Every Visit
Catching coverage issues upfront prevents delays that eat into your filing window.
5. Build a Corrected Claim Workflow
When a claim is denied, track the corrected claim deadline separately. Many payers allow only 60 days from the denial date to resubmit.
6. Keep Proof of Submission
Always retain clearinghouse transmission reports or certified mail receipts. If a payer claims they “never received” your claim, you need proof to appeal.
Exceptions to Timely Filing Limits
Under normal circumstances, missing the deadline means permanent denial. However, some rare exceptions exist.
Medicare Exceptions
According to CMS regulations, there are four specific situations that allow providers to request an extension:
- Administrative error by a Medicare contractor or DHHS employee
- Retroactive Medicare entitlement beneficiary receives coverage retroactively
- Retroactive entitlement involving state Medicaid agencies Medicaid recoups payment 6+ months after service
- Retroactive disenrollment from a Medicare Advantage plan
In each case, Medicare extends the timely filing limit through the last day of the sixth month following the month in which the provider received notice of the error or entitlement.
Commercial Payer Exceptions
- Payer system errors: If a payer experiences internal issues that delay processing, they may allow late submissions
- Retroactive eligibility: When a patient is approved for coverage after receiving care (e.g., backdated Medicaid enrollment), some payers restart the filing deadline from the eligibility confirmation date
- Public health emergencies or natural disasters: Payers may temporarily extend filing deadlines regionally
What Does NOT Qualify as an Exception?
Provider forgetfulness, staff turnover, billing software issues, or heavy patient volume do not qualify. Do not submit appeal requests on untimely claims for these reasons. Medicare explicitly states that claims denied for exceeding the time limit are not eligible for redetermination (the first level of appeal).
What Is the CO-29 Denial Code?
If you receive a denial with Claim Adjustment Reason Code (CARC) CO-29, it means: “The time limit for filing the claim has expired.” This is the payer’s way of saying your claim arrived too late. Unlike a coding denial that can be corrected and resubmitted, a CO-29 denial is usually final.
What If You Discover a Late Claim?
If you realize a claim was never submitted and the deadline has passed:
- Do not submit it. A late claim will be automatically denied with a CO‑29.
- Do not bill the patient. Most payers do not allow providers to bill patients for claims denied due to timely filing issues, though this can vary by contract.
- Check for an exception. Review the rare scenarios above. If none applies, write off the charge.
- Fix the process. Investigate why the claim was missed and implement safeguards.
Final Thoughts
Timely filing limits are among the strictest rules in medical billing. A single missed deadline can turn a fully reimbursable claim into a total loss. Unlike coding or authorization issues, there is usually no appeal.
The best defense is a proactive system: submit claims within 48 hours, track payer deadlines, monitor clearinghouse rejections daily, and treat corrected claims with the same urgency as initial submissions. By respecting the clock, you protect your revenue and keep your practice financially healthy.
Frequently Asked Questions
1. What is the timely filing limit for Medicare?
Medicare allows 12 months (365 days) from the date of service for most Part A and Part B claims. Claims submitted after this deadline are automatically denied.
2. What happens if I miss the timely filing deadline?
The claim will be denied with a CO‑29 code (timely filing limit expired). Unlike other denials, this is usually permanent and not eligible for appeal.
3. Do corrected claims have their own filing deadline?
Yes. Corrected claims often have a much shorter window typically 60 days from the date of the original denial or rejection.
4. Can I appeal a timely filing denial?
Generally no. For Medicare, claims denied for untimely filing are not eligible for redetermination. For commercial payers, exceptions are extremely rare. Focus on prevention.
5. Do Medicaid timely filing limits vary by state?
Yes. Some states (e.g., New York, Texas) allow only 90 95 days, while others (e.g., Florida, Ohio) allow up to 365 days.
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