Timely Filing Limit

Timely filing limits are contractually established deadlines by which a healthcare provider must submit a claim to an insurance payer in order to be eligible for reimbursement. Miss the deadline, and the payer will deny the claim with CARC code CO-29, and unless the provider can prove the original submission was timely, the revenue is permanently lost with very limited options for recovery.

Unlike most other denial categories, timely filing denials are difficult to appeal after the fact. They are one of the few denial types where the provider's recourse is genuinely limited, which makes prevention through proactive claim submission workflows far more valuable than back-end recovery.

What are the actual deadlines by payer?

Timely filing limits vary significantly by payer and plan type, which is one reason they are so frequently missed:

• Medicare: 12 months from the date of service (1 calendar year). Late filing exceptions exist in very limited circumstances, such as administrative error by a Medicare contractor.
• Medicaid: Varies by state, typically 90 days to 12 months from date of service. Some states allow extensions for specific circumstances such as late eligibility determination.
• TRICARE: Generally 12 months from date of service for most claims.
• Commercial payers: Highly variable. Common windows are 90 days, 180 days, and 365 days. Some aggressive managed care plans impose 60-day limits. A few payers for certain plan types may allow up to 24 months.

Because commercial payer limits are contract-specific and can change at contract renewal, billing staff should maintain a payer-specific timely filing reference that is reviewed when contracts are renegotiated.

When does the clock start?

For most claims, the timely filing clock starts on the date of service. However, there are situations where the start date is less straightforward:

Coordination of benefits: When the primary payer is billed first and then the secondary payer is billed for the remaining balance, many secondary payers start the timely filing clock from the date of the primary EOB, not the date of service. Common windows for secondary billing are 60-180 days from primary adjudication.

Retroactive eligibility: If a patient's insurance coverage is determined retroactively (for example, Medicaid enrollment that is backdated after a pending application is approved), the timely filing window typically starts from the date the retroactive determination was made, not the date of service.

Workers' compensation: Filing deadlines under workers' compensation are governed by state law and vary considerably.

Can timely filing denials be appealed?

In most cases, a timely filing denial can only be successfully overturned if the provider can demonstrate that the original claim was submitted before the deadline. Acceptable documentation typically includes clearinghouse submission reports with timestamps, payer portal acknowledgment records, or, for paper claims, certified mail receipts.

If the claim was submitted on time but the denial still came back as CO-29, the most likely explanation is that the payer did not receive or process the original submission. In this situation, the appeal consists of attaching proof-of-timely-submission documentation to a reconsideration request.

Without that documentation, the appeal will almost certainly fail. Payers do not grant exceptions based on provider oversight or administrative error.

How do high-performing practices prevent timely filing denials?

The most effective prevention strategy is submitting claims within 24-72 hours of service, well inside any payer's filing window. Practices that batch-submit weekly or hold claims waiting for documentation are most at risk.

Secondary billing queues require separate monitoring, since claims can appear "done" after primary adjudication but still require secondary submission within a separate deadline.

Clearinghouse rejection reports should be reviewed daily. A claim that fails clearinghouse validation is not considered submitted by the payer, and the filing clock continues running while the rejection sits unaddressed. A rejected claim that is not corrected and resubmitted within the payer's filing window becomes a timely filing denial by default, even though the provider believed the claim had been sent.