Timely filing: the deadline that quietly writes off revenue

A timely filing denial is not a documentation problem or a coding problem. It is a claim that was correct and payable, and simply arrived after the payer stopped counting. In most contracts, once that window closes there is no appeal that reopens it — the service was delivered, the cost was incurred, and the revenue is gone regardless of whether the claim was ever wrong.

That is what makes it different from every other denial category: it does not reward getting better at billing. A practice with a clean-claim rate that would satisfy any consultant can still lose real money to a deadline nobody was watching.

The clock starts on the date of service, not when someone notices the claim

Timely filing windows are calculated from the date a service was rendered, not from when a note is signed, an eligibility question is resolved, or a biller opens the encounter. Every day a claim sits unbilled for any reason — a documentation backlog, a credentialing question, a coordination-of-benefits delay — is a day subtracted from a deadline that is already running.

That matters because most practices track the revenue cycle from claim submission forward: days in A/R, first-pass rate, denial rate by reason code. None of those measures the pre-submission lag against the filing clock, because none of them start until the claim exists.

There is no single deadline — that is the trap

Medicare Part B has one fixed rule, set in federal regulation rather than contract: claims must be received no later than one calendar year after the date of service, with narrow, specifically enumerated exceptions, under 42 CFR 424.44. There is no provider discretion and no payer-specific negotiation.

Everything else varies, and assuming one payer's rule applies to another is itself a source of lost revenue. UnitedHealthcare is instructive precisely because it publishes no single number: its provider guidance directs practices to their own Participation Agreement for the applicable window, and illustrates only the mechanic — if the last date of service is May 1 and the agreement allows 90 days, all claim information including corrections must be received by July 30 (UnitedHealthcare provider guidance). If a national payer will not state one universal deadline, neither should a billing team assume one. Other commercial payers and Medicaid MCOs set their own windows by contract, and none is obligated to match Medicare, each other, or a state's fee-for-service policy — which matters more than it used to, since most Medicaid beneficiaries are now enrolled in managed care rather than fee-for-service, in shares that vary considerably by state, per MACPAC's enrollment data. The governing deadline is often the MCO's provider manual, not the state rule a team memorized. Behavioral health adds a further layer where a carve-out entity administers the specialty benefit under its own filing terms, separate from the medical plan — easy to miss if only the primary payer's rule gets checked. There is no universal number here; the only reliable answer is the one in the specific contract for the specific plan.

The appeal window is a second, separate clock

A claim filed on time but denied for a fixable reason is not safe. Once a denial posts, a new and usually shorter clock starts for correcting or appealing it, running independently of the original filing deadline — and often faster. Medicare Part B's structure illustrates the pattern, even though its numbers are federal rather than contractual: a first-level redetermination must be requested within 120 days of receiving the Medicare Summary Notice or remittance advice, and a second-level reconsideration within 180 days of the redetermination notice, under 42 CFR 405.942 and 405.962, each measured from receipt of the preceding notice. Commercial and Medicaid MCO appeal windows are contract-set the same way, and frequently shorter than the original submission deadline, not longer.

Why the window gets missed even when the team is trying

The math rarely fails because of one large mistake. It fails because several small, ordinary delays draw on the same fixed clock — a note signed a week late, an eligibility question that takes ten days, a secondary claim waiting on a primary EOB near the end of the window. Each is defensible on its own; each spends days that cannot be recovered once spent.

The industry-wide numbers describe how often that math loses. MGMA’s 2023 DataDive Practice Operations data set recorded a single-specialty aggregate rate of 8% for claims denied on first submission — the same rate it documented in 2019 — and a March 2024 MGMA Stat poll of 235 practice leaders found 60% reporting higher denial rates than a year earlier, against 11% reporting a decrease (MGMA Stat). Comparing those rates across organizations is harder than it looks, which is why HFMA’s Claim Integrity Task Force publishes standard denial-metric definitions rather than leaving each practice to define its own (HFMA). A claim that enters a correction cycle late in its filing window is a candidate to join the pile that never gets reworked — not because anyone decided to write it off, but because nobody was left with enough clock to finish.

What closes the gap

The practices that lose the least treat the deadline as a fact attached to each claim from the day of service, not something looked up after a denial arrives. Track age since date of service for anything still unbilled, not just A/R age for claims already submitted. Hold the specific payer-and-plan deadline as data tied to that claim rather than a number someone remembers approximately, and treat a denial's appeal deadline as a second countdown, visible next to the original filing deadline the moment the denial posts.

None of this substitutes for correct coding or clean documentation. It is what keeps a correct, well-documented claim from becoming unpayable for a reason that has nothing to do with whether it was ever right.

Resova iQ's RCM iQ module holds date of service, payer, plan and contract terms together on each claim, so filing and appeal deadlines age visibly rather than surfacing only after they have passed — using the same 837P submission, 277 acknowledgement and 835 remittance data the platform already handles. It does not file a correction or an appeal on its own; every submission goes out under the approvals a practice configures, and a person decides what happens with each flagged deadline.