Timely Filing Limits for Medical and Mental Health Claims: How They Work and How to Never Miss One

A timely filing limit is the deadline for a payer to receive a claim, counted from the date of service (or sometimes from the date of discharge or a primary payer’s payment). Medicare allows 12 months. Medicaid programs and commercial payers set their own limits, commonly from 90 days to one year, and your contract can shorten them. Miss the deadline and the payer denies the claim (usually code CO-29), and in-network providers generally cannot bill the patient for it.

Timely filing denials are one of the most painful losses in billing, because the service was real, the patient was covered and the claim was often correct. It simply arrived too late.

Deadlines by payer type

Payer type	Typical limit for original claims	Where to confirm
Medicare (Part B)	12 months from the date of service	Medicare rules; your Medicare Administrative Contractor
Medicare Advantage	Set by the plan and your contract; often shorter than original Medicare for in-network providers	Your contract and the plan’s provider manual
Medicaid (fee-for-service)	Set by each state, often within 12 months, sometimes much shorter	The state Medicaid provider manual
Medicaid managed care plans	Set by each plan within state rules	The plan’s provider manual and your contract
Commercial insurance	Commonly 90 days to one year	Your contract and the payer’s provider manual
Secondary claims	Often counted from the primary payer’s payment date	The secondary payer’s rules

We deliberately do not publish a single “limits by payer” list. Limits differ by plan, state, product and contract, and they change. The number that counts is the one in your contract. Keep a table of each payer’s limit for your practice and review it every year.

Deadlines that are easy to forget

The original claim is not the only deadline:

• Corrected claims often have their own window, counted from the original claim or its payment.
• Reconsiderations and appeals have separate limits. Medicare’s first-level appeal (redetermination) must be filed within 120 days of receiving the initial decision.
• Coordination of benefits: when a primary payer takes months to process, the secondary payer’s clock may already be running. Know which date each payer counts from.
• Retroactive eligibility: when a patient’s coverage is approved backdated (common with Medicaid), special filing rules often apply. Ask the payer.

How to prove a claim was filed on time

If a payer says a claim was late and you believe it was not, you need evidence of the original submission:

• A clearinghouse acceptance report (for example 999 and 277CA reports) showing the payer accepted the claim on a date inside the limit
• A payer acknowledgment or claim number from the original submission
• For paper claims, proof of mailing, such as certified mail receipts

Keep these reports. Many practices lose timely filing appeals simply because nobody saved the acceptance report.

A rejected claim is not a filed claim

A claim rejected by the clearinghouse, or by the payer before it enters their claims system, is treated as never filed. If rejections are not checked daily, a claim can sit in a rejection list while its deadline passes. This is one of the most common causes of timely filing losses we see.

How we make sure no claim misses its deadline

• Claims go out within 24 hours of receiving charges.
• Rejections are worked the same day.
• Unpaid claims are followed up weekly, sorted by how close each one is to its payer’s deadline.
• Denials are worked within 5 business days, well inside appeal windows.

If you have old unpaid claims, our A/R recovery team works the ones nearest to their deadline first. For how to read the denial itself, see denial codes explained.

Filing limits change and vary by contract. Always confirm the current limit in your payer contract or provider manual.

Frequently asked questions