What Is the Timely Filing Limit for Insurance Claims? (By Major Payer)

A claim can be medically necessary, correctly coded, fully documented, and still become unpayable because it arrived at the payor one day after their deadline.

That is what a timely filing limit does.

Unlike most denial reasons, missing the filing window closes the claim permanently. There is no correction to make, no code to fix, and in most cases no patient balance to collect. The revenue is simply gone.

This guide covers the timely filing deadlines that practice managers and billing teams need to know by payor, including corrected claims, appeals, and what denial code to expect when the window closes.

Disclaimer: This article is provided for general educational and informational purposes only. It does not constitute legal, financial, or compliance advice. Timely filing limits vary by payor, plan type, provider contract, and state law. Always verify current deadlines in your specific provider agreement and the payor’s current provider manual before submitting claims or appeals.

Key Takeaways

• CO-29 is the denial code for expired timely filing. It is a contractual write-off, the provider absorbs it and cannot bill the patient.
• Commercial payor deadlines are typically 90 days. Medicare gives 12 months. Medicaid varies by state.
• Appeal windows are separate and shorter than initial filing windows. United Healthcare’s commercial appeal window is 65 days, the shortest among major payors.
• Your provider contract governs. Every number in this guide is a starting point, not a substitute for your current agreement.

What Is a Timely Filing Limit?

A timely filing limit is the deadline a payor sets for receiving a claim after the date of service or discharge. Claims submitted after the window closes are denied with CO-29 and become permanent write-offs under most contracts. The provider cannot bill the patient for the denied amount.

Corrected claims and appeals carry their own separate deadlines; missing the initial window does not always close the appeal window, but it usually limits options significantly.

Quick-Reference Table: Timely Filing Limits by Major Payor

Sources: 42 CFR 424.44 (Medicare); payor provider manuals and public-facing provider resources verified June 2026. Your provider contract may specify different windows, always verify.

Medicare Timely Filing Limit

The Medicare timely filing limit is 12 months from the date of service, governed by 42 CFR 424.44. Medicare uses the receipt date, not the postmark or electronic submission timestamp.

A claim for a July 1, 2025 service must be received by July 1, 2026. One day late means automatic denial with no standard appeal pathway.

CO-29 on a Medicare claim is not appealed through redetermination. It requires a claim reopening under CMS Publication 100-04, Section 70.7, and only four CMS-recognized exceptions qualify¹:

• Retroactive entitlement
• Administrative error
• Beneficiary hospitalization
• Provider administrative error caused by another federal agency

The timely filing limit for Medicare applies to Part A and Part B.

What is Medicare timely filing limit for Medicare Advantage?

Original Medicare’s 12-month rule does not apply. Each MA plan sets its own window, though CMS sets a minimum floor of 365 days.

What is the timely filing limit for Medicare redeterminations: 120 days from the denial notice.

Medicaid Timely Filing Limit

The Medicaid timely filing limit varies by state. Federal law under 42 CFR 447.45 sets a maximum of 12 months from the date of service, but states routinely set shorter windows through their State Plans or managed care contracts.²

Common state examples for Medicaid timely filing limits:

• New York applies 90 days for non-institutional claims.
• Pennsylvania applies 180 days.
• Texas Medicaid applies 95 days for acute care and 12 months for long-term care.

Practices billing Medicaid across multiple states must track each state’s deadline separately. A single missed state-specific window is a permanent write-off at whatever rate Medicaid pays.

United Healthcare Timely Filing Limit

• The united healthcare timely filing limit for commercial in-network providers is 90 days from the date of service.³
• UHC Medicare Advantage gives 365 days.
• Community Plan (Medicaid) limits align with state-specific guidelines and typically run 90 to 180 days.
• The united healthcare appeal timely filing limit is 65 days for commercial plans, the shortest appeal window among major commercial payors.
• Medicare Advantage appeals allow 60 days.

What is the timely filing limit for united healthcare on corrected claims: most UHC plans require corrections within 180 days of the original remittance.

BCBS Timely Filing Limit

BCBS timely filing limit rules vary significantly by affiliate.

• Blue Cross Blue Shield operates as 34 independent state plans, and BCBS timely filing windows range from 90 days (BCBS Massachusetts, Anthem BCBS) to 365 days (BCBS North Carolina, Florida Blue, Premera, and the Federal Employee Program).⁴
• BCBS Texas timely filing limit is 365 days for commercial Blue Choice PPO plans and 95 days for Medicaid and CHIP.

Timely filing for BCBS claims also depends on network status and line of business. Appeal windows run 60 to 180 days depending on the affiliate and state law.

Timely filing BCBS practices that treat all Blue Cross plans as a single entity generate systematic errors. The affiliate that issued the patient’s card sets the rule, not the BCBS national brand.

Why Routine Billing Audits Are Essential for Protecting Practice Revenue shows exactly what a structured audit surfaces in deadline and denial management.

Cigna Timely Filing Limit

The Cigna timely filing limit is 90 days for in-network commercial providers and 180 days for out-of-network providers.⁵ Cigna healthcare timely filing limit for Medicare Advantage runs through December 31 of the following calendar year.

Cigna timely filing limits are measured from the date of service for most claims. For COB claims, what is Cigna timely filing limit on secondary submissions: 90 days from the primary payor’s EOB.

*California is a state exception; state law extends the window to 365 days.

Cigna Corrected Claim Timely Filing Limit

The Cigna corrected claim timely filing limit for commercial plans is 90 days from the date of the original remittance advice for in-network providers, and 180 days for out-of-network. The corrected claim clock runs from the remittance date, not the date of service. It does not reset or extend the original DOS-based filing window.⁵

Cigna Appeal Timely Filing Limit

• The Cigna appeal timely filing limit is 180 days from the initial payment or denial notice for commercial plans.
• Medicare Advantage appeal deadline is 65 days.
• Cigna must complete commercial appeal reviews within 60 days of receipt.⁵

Aetna Timely Filing Deadline

The Aetna timely filing deadline for in-network commercial providers is 90 days from the date of service.

Out-of-network providers have 12 months.

Medicare Advantage follows the CMS-mandated 365-day floor.⁶ Appeal deadlines are 180 days for a Level 1 reconsideration and 60 days for Level 2. Medicaid managed care plans apply 180 days.

What Denial Code Means a Claim Was Filed Late?

The timely filing denial code is CO-29. It is a Claim Adjustment Reason Code (CARC) defined by X12 as “the time limit for filing has expired.”

The group code CO signals contractual obligation: the provider writes off the amount under the network contract and cannot bill the patient. The denial code for timely filing appears on both professional CMS-1500 and institutional UB-04 claims across Medicare, Medicaid, and all commercial payors.

CO-29 on a commercial claim can be appealed with documented proof of timely submission: clearinghouse acceptance reports, EDI acknowledgment timestamps, or certified mail logs. On Medicare, CO-29 requires a claim reopening under CMS rules, not a standard redetermination, and only qualifies under the four recognized CMS exceptions.¹

A CO-29 denial cannot be overturned by improving the coding, adding documentation, or appealing on clinical grounds. The only question the payor reviews is whether the claim was received within the filing window.

Understanding the Most Frequent Denial Codes in 2026 covers CO-29 alongside the other denial codes that generate the most preventable write-offs.

Timely Filing Limits in 2026: The Bottom Line

Every dollar a timely filing denial takes is permanent. Unlike coding errors or missing authorizations, a CO-29 write-off has no corrective path once the window closes. The only protection is submitting within the tightest deadline in your payor mix and tracking corrected claims and appeal windows as aggressively as initial claims, which is difficult for practices relying on their in-house billing teams.

A3 Medical Billing is a medical billing company, that most USA practices trust for medical billing services, RCM services, and credentialing services with a 99% clean claim rate on first submission, no long-term contracts, and no hidden fees.

As a revenue cycle management company for independent practices, A3 gives you the expertise to track every payor window, submit within 48 hours of charge capture, and appeal CO-29 denials with documented proof before the appeal window closes.

A3’s workflow means timely filing denials become rare rather than routine. Contact A3 for a free billing audit and find out which payor deadlines your current workflow is putting at risk.

Frequently Asked Questions

Can a timely filing denial be appealed and what is needed to win?

A CO-29 denial on a commercial claim can be appealed with documented proof the claim was received within the filing window: an EDI acceptance report, clearinghouse timestamp, or certified mail receipt showing the original submission date. Clinical documentation, coding corrections, and authorization records are irrelevant — the only issue is whether the claim arrived on time. On Medicare, CO-29 requires a claim reopening under CMS Publication 100-04 Section 70.7, not a standard redetermination.

Does the timely filing clock start from the date of service or the date of discharge?

For professional claims it starts on the date of service. For inpatient institutional claims it typically starts on the date of discharge. For COB secondary claims, most payors restart the clock from the primary payor’s remittance date, commonly 90 days from the primary EOB. Practices that apply the date-of-service rule to secondary claims generate preventable CO-29 denials on claims that were still within their actual window.

Does Medicare’s timely filing limit apply to Medicare Advantage plans?

No. Original Medicare’s 12-month rule under 42 CFR 424.44 applies only to Part A and Part B fee-for-service claims. Medicare Advantage plans are administered by private insurers and set their own filing windows, subject to a CMS floor of 365 days. A practice applying the 12-month Original Medicare rule to an MA plan with a 90-day window will generate systematic CO-29 denials on claims filed after day 90.

What documentation proves a claim was filed on time?

Clearinghouse EDI acceptance reports and 277CA acknowledgment files are the strongest evidence because they include a timestamp showing the payor or clearinghouse received the claim on a specific date. Certified mail return receipts work for paper claims. Payer portal submission confirmation screens with timestamps work if printed or saved at submission. Billing staff verbal confirmation and billing system internal notes do not qualify as proof with any major payor.