The FSA run-out period is the window after your plan year ends when you can still submit reimbursement claims for eligible medical expenses you already incurred during that plan year. It is a filing extension, not a spending extension. You cannot use it to see a doctor, fill a new prescription, or buy anything new and have your old FSA cover it. The service or purchase had to happen while the plan year was still active; the run-out period only gives you extra time to get the paperwork in.
What the Run-Out Period Actually Covers
The rule that governs everything else is the incurred date. A dental cleaning in November that you paid a copay on but never submitted a receipt for qualifies, because the service happened during the plan year. A teeth whitening appointment in February of the new year does not, no matter how much money is sitting in your old account.
Federal regulations define the run-out period as a window after the plan year ends during which participants can submit claims for reimbursement of qualified expenses incurred during that plan year. Your employer decides whether to offer one and how long it runs, but whatever deadline the plan sets has to apply to every participant equally.
The date of service on your receipt is what determines which plan year the claim belongs to. A January 5 service date gets processed against the new plan year’s balance even if you submit it during the old year’s run-out window. Check every receipt before filing.
How Long You Have to File
There is no federally mandated length. Your employer picks the duration and writes it into the plan document. The most common choice is 90 days, which for a calendar-year plan puts the filing deadline at March 31. Some employers offer 30 or 60 days; others go longer.
Missing the deadline by a single day forfeits your right to reimbursement. The plan administrator has no discretion to make exceptions, and your employer cannot bend the rules for one employee without risking the tax status of the entire cafeteria plan under Section 125 of the Internal Revenue Code. That risk is what keeps the deadline rigid.
If you do not know your plan’s specific deadline, look at your Summary Plan Description or benefits portal. This is not a date to research after the fact.
Run-Out Period vs. Grace Period vs. Carryover
Three separate FSA features sound alike and get mixed up constantly. Knowing which one your plan offers changes what you can actually do with leftover funds.
A run-out period lets you file old claims for old expenses. Nothing more.
A grace period extends your spending window by up to two and a half months after the plan year ends. During a grace period you can incur brand new eligible expenses and pay for them from your prior year’s balance. If your plan year ended December 31 and your employer offers the full grace period, a doctor visit on March 1 can be reimbursed from last year’s funds. Anything unspent after the grace period expires is forfeited.
A carryover rolls a set dollar amount of unused funds into the next plan year. For the 2026 plan year, the IRS allows plans to carry over up to $680 into 2027. Your employer can set a lower cap but not a higher one. Balances above the cap are forfeited. Carried-over funds merge into your new plan year balance and can be spent on any eligible expense incurred during that new year.
A plan cannot offer both a grace period and a carryover for the same FSA — it has to pick one. A run-out period can coexist with either, because it does something different. You might have a plan with a $680 carryover and a 90-day run-out period at the same time.
Your Debit Card Stops Working
This is where people get blindsided. Most FSA debit cards are deactivated at the end of the plan year or shortly after. Even with money still in the account and a run-out period ahead, you generally cannot swipe the card during that window. The card was a real-time payment method during the plan year; the run-out period is a claims-filing period.
Some card transactions from the plan year may still need documentation. Purchases at pharmacies and certain FSA-eligible retailers auto-substantiate at the point of sale, but many transactions at general medical offices get flagged for follow-up. If your administrator sent a substantiation request in November that you set aside, the run-out period is your last chance to provide the receipt before the charge is denied and potentially recouped from your paycheck.
Documentation You Need
Every run-out claim needs proof that you incurred an eligible expense during the plan year. The core document is an itemized receipt or bill showing four things: patient name, provider name, date of service, and amount charged. A credit card statement showing a payment to a medical office is not enough on its own because it does not describe the service.
For expenses partially covered by insurance, most administrators require an Explanation of Benefits from your carrier. The EOB shows what insurance paid, what you owe, and confirms the service. EOBs are among the most reliable pieces of documentation because they contain everything the administrator needs in one place. If you had a procedure in December but the EOB did not arrive until February, this is exactly what the run-out period is for.
How to File
With the debit card deactivated, you submit claims manually. Most administrators offer an online portal where you upload scanned receipts and EOBs, and many have mobile apps that let you photograph documents and submit from your phone. Electronic submission creates an instant record of the filing date, which matters if the timing gets disputed.
Paper claims are usually accepted at a designated processing address. Use a trackable shipping method. A claim that arrives after the deadline is dead on arrival regardless of the postmark, and you will want proof of delivery if the timing is tight.
Processing speed varies. Some administrators clear verified claims in one to two business days; others take longer, particularly during peak run-out season when volume spikes. Reimbursement lands by direct deposit or mailed check depending on your account settings. Watch your account through the portal after submitting so you can fix any issue while there is still time.
If You Left Your Job
Leaving a job does not automatically wipe out your FSA balance. Most plans provide a run-out period for terminated employees, typically 90 days from the date coverage ends. Some plans extend health FSA coverage through the end of the month you leave, with the run-out starting after that; others cut coverage on your last day. Your plan document controls which applies.
You can only claim reimbursement for expenses incurred while your coverage was active. If coverage ended March 15, a doctor visit on March 20 is not reimbursable no matter what the balance is. Anything unclaimed after the run-out window closes is forfeited permanently. There is no mechanism for a former employer to refund unused FSA money to you individually.
You may have the option to continue your health FSA through COBRA, which would extend your ability to incur new eligible expenses. COBRA for an FSA is rarely worth it because you pay both the employee and employer contributions plus a 2% administrative fee, but if you have a large balance and anticipated medical costs, run the numbers before deciding.
What Happens to Money You Do Not Claim
Unused FSA funds that survive the run-out period without a valid claim are forfeited. The IRS prohibits converting unused health FSA amounts into cash or any other benefit. Where the forfeited money goes depends on whether your employer’s plan is governed by ERISA, which covers most private-sector plans.
For ERISA-governed plans, forfeited funds are plan assets and must be used for the exclusive benefit of participants. In practice that usually means offsetting plan administration costs or reducing future employee contributions. For plans not subject to ERISA, such as some government employer plans, the employer has more flexibility and may keep the funds. Either way, the money cannot be paid back to you based on how much you personally lost. Any distribution has to be reasonable and uniform across participants.
This is the real cost of a missed deadline. You contributed pre-tax dollars, received a legitimate medical service, paid out of pocket, and lost the reimbursement because paperwork was late. On a $500 unclaimed expense that is roughly $350 to $400 in after-tax money gone, depending on your bracket.
Appealing a Denied Claim
If a claim is denied, you have the right to appeal. Under ERISA, your plan must give you at least 180 days from the date you receive the denial notice to file a formal appeal. The denial notice itself has to state the specific reason for the denial, cite the plan provisions the decision rests on, describe any additional documentation that could support the claim, and explain the plan’s appeal procedures.
File the appeal in writing to your plan administrator. Explain why you disagree, reference the plan provisions or IRS rules that support your position, and include copies of supporting documents: the original receipt, an EOB, a letter of medical necessity, or medical records if relevant. Keep copies of everything you send.
The most common reasons for run-out denials are a service date outside the plan year, missing or incomplete documentation, and expenses that do not qualify as eligible medical costs under IRS rules. Most of these are fixable on appeal if you produce the right paperwork. A denial for missing the run-out deadline itself is almost never reversible, because the administrator has no discretion to extend it.