For most medical insurance claims, you have somewhere between 90 days and one full year from the date of service to submit, and the exact deadline depends on what kind of coverage you have. Medicare fixes the window at one calendar year. Medicaid deadlines are set state by state. Private plans, including employer coverage and marketplace policies, write their own deadlines into the plan documents. Miss the window, and the insurer almost always refuses to pay, no matter how clearly the treatment was covered.
Filing Deadlines by Plan Type
There’s no single rule. What applies to you depends on the source of your coverage.
- Employer-sponsored plans. Deadlines are set in the plan documents and vary widely, from 90 days after treatment up to a year. Federal law doesn’t set a specific number but requires the timeframe to be reasonable and disclosed in your Summary Plan Description.
- Individual and marketplace plans. These follow state insurance regulations. Most states require a reasonable filing window, but insurers set the specific length. Your policy documents or member services line will have the number.
- Medicare (Parts A and B). All fee-for-service claims must reach Medicare within one calendar year of the date of service. A visit on April 15, 2026 has to be filed by April 15, 2027. After that, Medicare won’t pay its share except in a few narrow situations.1eCFR. 42 CFR 424.44 – Time Limits for Filing Claims
- Medicaid. Deadlines vary by state, generally 90 days to one year. Because Medicaid is jointly administered by federal and state governments, no single national deadline applies. Check your state Medicaid agency’s provider manual.
One detail that trips people up: the clock almost always starts on the date of service, not the date you receive a bill. Billing delays from your provider can quietly burn through your filing window before you know a claim exists.
Whether You Actually Have to File
Most patients never submit a claim themselves. When you see an in-network provider, the provider’s billing office files with your insurer as part of their contract. You don’t touch the paperwork, and the deadline is their problem.
Out-of-network care is where the deadline becomes yours. Because the provider has no contract with your insurer, they have no obligation to file. Some will as a courtesy; many won’t. You pay upfront, then download a claim form from your insurer’s website, attach the itemized bill, and submit before the deadline. Most insurers accept submissions through their member portal, which is faster and generates an automatic record.
Medicare works differently. Doctors and suppliers enrolled in Medicare are required by law to file claims for you within the one-year window.2Medicare. Filing a Claim If a provider refuses, you can file it yourself or report the provider to Medicare.
Where Your Deadline Is Written Down
If your coverage comes through an employer, the plan is almost certainly governed by the Employee Retirement Income Security Act. ERISA doesn’t set a specific filing deadline, but it requires plans to establish claims procedures that are reasonable and don’t “unduly inhibit or hamper” your ability to file.3U.S. Department of Labor. Benefit Claims Procedure Regulation FAQs A 10-day filing window, for example, wouldn’t survive that standard.
The actual deadline lives in your Summary Plan Description, which you receive when you enroll.4U.S. Department of Labor. Filing a Claim for Your Health Benefits If you’ve lost it, your plan administrator (usually HR) has to provide a copy on request. The SPD also spells out what documentation you need and how long the plan has to respond.
What Happens If You Miss the Window
Insurers treat filing deadlines as hard cutoffs. Once the window closes, the plan has no obligation to process the claim, even for care that was clearly covered and perfectly documented. It comes back denied as untimely, and you owe the full amount.
The damage doesn’t stop at that one bill. A denied claim doesn’t count toward your deductible or out-of-pocket maximum, because the insurer never processed it. Money you spent on that treatment does nothing to push you closer to the point where the plan picks up a bigger share. If you were counting on a major procedure to clear your deductible for the year, a late-filing denial erases that.
The picture changes when an in-network provider caused the delay. Most provider contracts prohibit billing you for amounts the insurer would have paid had the claim been filed on time. If your in-network doctor’s office drops the ball, the provider generally absorbs the loss and you shouldn’t receive a balance bill. If one arrives anyway, call your insurer and ask them to enforce the contract.
When a Late Claim Can Still Be Accepted
Deadlines aren’t always absolute. Both Medicare and private plans recognize a handful of situations where a late claim isn’t the patient’s fault.
Medicare
Medicare will extend the filing deadline when a Medicare contractor or government employee caused the delay through error. It also allows extensions when a beneficiary wasn’t enrolled in Medicare at the time of service but later received retroactive coverage, and when a beneficiary was retroactively disenrolled from a Medicare Advantage plan after the plan had already recouped its payment from the provider.1eCFR. 42 CFR 424.44 – Time Limits for Filing Claims These are narrow. Not knowing about the deadline doesn’t qualify.
Private Plans
Many private plans include language allowing extensions for extenuating circumstances. If you were hospitalized, mentally incapacitated, or otherwise physically unable to manage your affairs during the filing window, most will consider granting more time. Documentation is what matters: a letter from a treating physician, medical records confirming the incapacity, and a claim filed promptly once you’re able.
Provider errors are another common basis for asking for an extension. If a billing office sent the claim to the wrong insurer, used an incorrect policy number, or simply never filed, get a written explanation of the error and submit it with the late claim. Some plans run a separate, shorter clock that starts when the error is discovered, so move quickly.
A majority of states follow some version of the notice-prejudice rule, which prevents an insurer from denying a late claim unless the insurer can show the delay actually harmed its ability to investigate or process the claim. Application varies by state, and not every state extends the rule to health insurance. If your claim was only slightly late and the insurer wasn’t disadvantaged, the doctrine can give you leverage in an appeal.
When You Have Two Plans
Coordination of benefits rules decide which of your plans pays first. The secondary insurer typically won’t process anything until the primary insurer has issued a decision, which creates a timing problem: the secondary plan’s deadline may run from the date of service, but you can’t file until the primary is done.
Many secondary plans handle this by starting their clock from the date of the primary insurer’s Explanation of Benefits rather than the date of service. A plan might allow 180 days from the date of service or 60 days from the primary EOB, whichever is later. Check the SPD for the exact language. If the primary insurer takes months, file with the secondary immediately after the primary EOB arrives. A few extra weeks can push you past the deadline.
Proving You Filed on Time
The most common preventable claim problem isn’t missing the deadline. It’s not being able to prove you met it. If the insurer says they never received your submission, the burden is on you.
Electronic filing through the insurer’s portal generates the clearest paper trail. You’ll receive a confirmation number or email after you submit. Save it. Providers filing electronically get an automated acknowledgment of receipt plus status notifications as the claim moves through processing, and those records are strong evidence of timely filing.
For paper claims, send by certified mail with return receipt requested. The green card that comes back proves both delivery and date. Regular mail offers no proof. Keep photocopies of the claim form, itemized bills, and any supporting records.
Keep a simple log either way: date of service, date submitted, confirmation or tracking number, and any follow-up calls with the insurer. It feels tedious until the one time it saves you thousands of dollars.
Appealing a Denial for Late Filing
A late-filing denial isn’t necessarily the end. You have appeal rights, and they’re worth using when the delay wasn’t your fault.
Internal Appeal
Under ACA rules, you have 180 days from the date you receive the denial notice to file an internal appeal with your insurer.5HealthCare.gov. Internal Appeals ERISA plans follow the same 180-day window.3U.S. Department of Labor. Benefit Claims Procedure Regulation FAQs In the appeal, explain why the claim was late and attach evidence: proof of submission if the insurer claims it wasn’t received, a provider’s letter documenting a billing error, or medical records showing incapacity. The insurer has to review and respond in writing.
External Review
If the internal appeal fails, you can request an independent external review. You have four months from the final internal denial to file. An outside reviewer with no ties to your insurer decides the case. Standard reviews are resolved within 45 days; urgent medical situations get expedited reviews within 72 hours. The federal external review process is free to you, and some state-run processes charge up to $25.6HealthCare.gov. External Review
External review helps most when there’s a factual dispute about whether you actually filed on time or whether the deadline was clearly communicated. For a straightforward miss with no mitigating circumstances, the odds of reversal are low. When there’s real ambiguity in the record, though, it can be the deciding step.