Timely filing limits by payer: 2026 quick reference

A clean, medically justified claim that misses its filing deadline is not read on the merits at all. It is returned or denied for untimeliness, full stop, regardless of how strong the underlying documentation is. The problem is that the deadline itself is not one number: it varies by payer, by whether the provider is in-network, sometimes by state, and it is a genuinely different clock from the separate reconsideration or appeal deadline that starts later.

The one genuinely simple rule: Medicare

Medicare (Original, Part B) sets its timely filing limit at 12 months, one calendar year, from the date of service, fixed by federal regulation at 42 CFR 424.44 rather than by individual contract. That means it does not vary by Medicare Administrative Contractor, which makes it the single most reliable figure in this entire list. The separate redetermination, first-level appeal, deadline is 120 days from the date of the initial determination, a different clock entirely from the 12-month filing window.

Commercial payers: what we can and cannot confirm

Commercial payer timely filing limits are set by individual provider contracts, published guidance, and sometimes state regulation, and they are far less centrally documented than Medicare's. The figures below are current as of August 2026, drawn from our own payer-by-payer reference, each carrying its own confidence flag depending on how directly we could confirm it.

Why the internet disagrees with itself on this

Search for almost any commercial payer's timely filing limit and you will find confident, conflicting answers across billing-agency blogs, each citing the others rather than a primary source. Molina Healthcare is a useful illustration of why: state Medicaid limits under the Molina umbrella range from 95 days in Texas to 365 days in Ohio and Kentucky, plus a separate 365-day limit for Molina Medicare Advantage nationally, all under one brand name. A single "Molina timely filing limit" headline is, at best, true for one specific state and product, and at worst simply wrong for the claim in front of you.

How to actually confirm your own deadline

1. Check your own participation agreement first, not a general web search. Negotiated contracts frequently set a different window than the payer's default published policy.
2. Confirm which clock applies to your claim type. Some payers measure from the date of service, others from a discharge date for inpatient claims, or from a primary payer's EOB date for secondary claims.
3. Separate the filing deadline from the appeal deadline. These are two different clocks, and confusing them is one of the most common reasons a valid reconsideration is filed too late, as our guide to writing a reconsideration request covers in more detail.
4. Re-check state-specific rules for Medicaid, Blue Cross Blue Shield plans and regional payers. These operate as collections of state or regional entities under one brand, and a national figure rarely applies uniformly.

If a claim already denied for timely filing

A CO-29 timely filing denial is worth appealing aggressively, but only when you have specific proof: a clearinghouse or EDI acceptance report showing the original claim was actually received within the deadline, or documentation of a good-cause exception the payer itself caused, such as a late eligibility response or retroactive enrollment. Without that proof, the deadline has already done its job, and the corrective action is prevention on the next claim, not appeal on this one.

Frequently asked questions

Is the timely filing limit the same as the appeal deadline?

No, these are two separate clocks. The timely filing limit governs how long you have to submit the original claim; the reconsideration or appeal deadline is a separate, usually shorter window that starts from the date of the denial or remittance, not the date of service.

Why don't you publish a single figure for every payer?

Because for several major payers, no single national figure actually exists; the real answer varies by state, product, or contract. Publishing one confident number in those cases would be more misleading than useful, so we report what we can confirm and flag clearly where we cannot.

Does the timely filing clock start from the date of service or the date I submit the claim?

Almost always from the date of service, or for inpatient claims sometimes the discharge date, not from when you happen to submit the claim. Check the specific payer's clock-start rule, since a small number of scenarios, such as secondary claims, measure from a different date, like the primary payer's EOB date.

What should I do if my contract states a different limit than the payer's published default?

Your own contract governs. A published default is a general policy that a negotiated participation agreement can, and often does, supersede for the parties to that contract, so always check your own agreement before relying on a general figure.