HSA and FSA Eligible Health Tests: The Complete 2026 Guide

Most diagnostic lab tests are HSA and FSA eligible because laboratory fees are qualified medical expenses. See the IRS rule, the 2026 limits, which tests qualify, and what documentation your administrator wants.

Published

October 1, 2026

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Most diagnostic health tests are HSA and FSA eligible. The IRS counts laboratory fees that are part of medical care as a qualified medical expense, so blood panels, hormone tests, cancer screening, imaging, and most at-home test kits can usually be paid for with pre-tax HSA or FSA money. What changes the answer is not the test’s name or where you bought it. It is whether the test served a medical purpose, and whether you can show your plan administrator that it did.

Quick summary

• The rule: a qualified medical expense is spending on the diagnosis, cure, mitigation, treatment, or prevention of disease, under Internal Revenue Code section 213(d) and IRS Publication 502. Laboratory fees that are part of medical care are listed by name.
• Diagnostic lab work usually qualifies. Publication 502 specifically allows an annual physical examination and diagnostic tests by a physician, even when you have no symptoms.
• Preventive screening is not a loophole. Prevention of disease is written into the definition, so age-based and risk-based screening is medical care, not general wellness.
• General health is the line that fails. Publication 502 excludes expenses merely beneficial to general health. Supplements and purely cosmetic items sit on that side.
• 2026 limits: HSA contributions are capped at $4,400 self-only and $8,750 family, plus $1,000 more at age 55 or older. A health FSA caps employee salary reductions at $3,400, with up to $680 of carryover if the plan allows it.
• Your administrator decides your claim. The IRS sets the floor. An employer’s FSA can be stricter, so confirm before you buy if the amount matters.
• At Mito: choose “Pay with HSA/FSA” at checkout and pay through Flex, Mito’s HSA and FSA payments partner. Flex emails an itemized receipt. Supplements are excluded from that rail, and a small number of individual products are too, so the option only appears when every item in your cart is eligible.

This guide is general information about how the IRS rules work. It is not tax advice, and it is not a determination about your plan.

What makes a health test HSA or FSA eligible

A health test is HSA or FSA eligible when it is medical care under the IRS definition. HSAs and FSAs both borrow the same standard, so the answer does not change between the two accounts.

The IRS definition of medical care

IRS Publication 502 defines medical expenses as “the costs of diagnosis, cure, mitigation, treatment, or prevention of disease and for the purpose of affecting any part or function of the body.” That phrasing comes from Internal Revenue Code section 213(d). Publication 969, which covers HSAs and other tax-favored health plans, defines an HSA qualified medical expense as medical care under that same section 213(d), for you, your spouse, and your dependents, to the extent it is not reimbursed by insurance.

Two entries in Publication 502 do most of the work for testing:

• Laboratory fees. You can include “the amounts you pay for laboratory fees that are part of medical care.”
• Physical examination. You can include “the amount you pay for an annual physical examination and diagnostic tests by a physician,” and Publication 502 is explicit that you do not need to have symptoms for this to count.

Those two entries are why ordinary blood work is one of the least controversial things an HSA or FSA can buy.

Medical purpose versus general health

The failing side of the line is also written down. Publication 502 says medical care expenses “don’t include expenses that are merely beneficial to general health, such as vitamins or a vacation.”

In practice, the question is what the spending is for, not what it is called. A thyroid panel ordered because you are tired, gaining weight, or being monitored on thyroid medication is diagnosis and monitoring. The same panel bought with no screening or clinical reason at all is the case an administrator is most likely to push back on. Most testing people actually buy sits comfortably on the medical side, because they are checking for a condition, following up on a previous result, or screening at an age or risk level where screening is recommended.

How preventive screening is treated

Preventive screening is medical care. Prevention of disease is part of the section 213(d) definition, so a screening test does not need a diagnosis behind it to qualify.

There is a separate and often confused rule about high deductible health plans. A plan can cover certain preventive care before you meet your deductible without losing its HSA-qualified status, and the IRS maintains that preventive care list. Notice 2024-75 is the most recent expansion, and it states that “all types of breast cancer screening for individuals who have not been diagnosed with breast cancer are treated as preventive care.” That notice governs what your health plan may cover before the deductible. It does not govern whether an expense you pay yourself is HSA eligible. Those are two different questions, and a test can be a qualified medical expense without appearing on the preventive care safe harbor list.

Who actually decides

Three parties have a say, and only one of them looks at your specific purchase.

1. The IRS sets the definition of medical care. It does not pre-approve individual tests.
2. Your plan administrator reviews substantiation. For a health FSA, an employer can be stricter than the IRS floor and limit what its plan reimburses.
3. You, if you have an HSA. Nobody approves an HSA withdrawal in advance. You keep the receipt and you carry the risk if the IRS later disagrees.

If an amount is large enough that a denial would matter, ask your administrator before you buy.

2026 HSA and FSA limits at a glance

The 2026 HSA figures come from IRS Revenue Procedure 2025-19. The health FSA figures come from the IRS annual inflation adjustments for tax year 2026.

The catch-up amount is set in statute at $1,000 and is not indexed for inflation, so it does not move year to year the way the contribution limits do.

HSA rollover versus FSA use it or lose it

An HSA balance is yours. It rolls over every year, it follows you when you change jobs, and you can reimburse yourself for a qualified expense years after you paid for it, as long as the expense happened after the HSA was established and you kept the receipt.

A health FSA does not roll over by default. Depending on how your employer wrote the plan, you may get one of the following, but not both:

• A carryover of up to $680 of unused 2026 salary reduction money into the next plan year.
• A grace period of up to two and a half months after the plan year ends, during which new expenses can still be incurred against last year’s balance.

Separately, most plans give you a run-out period: extra time to submit claims for expenses you already incurred during the plan year. A run-out period does not let you spend leftover money on new purchases, which is the most common misunderstanding. For how to use money that is about to expire, see how to spend leftover FSA money before the deadline.

HSA and FSA eligible tests by category

Blood work and metabolic panels

Routine blood work is the clearest case. A complete blood count, a comprehensive metabolic panel, a lipid panel, and glucose or HbA1c testing are diagnostic assays run by a certified laboratory, so they are laboratory fees that are part of medical care. They qualify whether you are investigating a symptom, monitoring a known condition, or screening based on age and risk.

See CBC test cost, comprehensive metabolic panel cost, lipid panel cost, and HbA1c test cost for what these cost at different providers.

Hormone and thyroid testing

Thyroid panels including TSH, free T4, and free T3, plus testosterone, estradiol, DHEA-S, and sex hormone binding globulin, are ordinary diagnostic lab tests. They are HSA and FSA eligible on the same basis as any other laboratory fee, and they are commonly ordered to evaluate fatigue, weight change, cycle irregularity, low libido, or fertility questions.

See thyroid panel cost, testosterone test cost, and estradiol test cost.

Cancer screening and specialized diagnostics

Cancer screening is medical care because prevention and diagnosis of disease are both inside the IRS definition. That covers a PSA test, the lab work around a colonoscopy, and multi-cancer early detection blood tests. Most insurance plans do not yet cover multi-cancer early detection screening, so it is usually paid out of pocket, which is exactly the situation HSA and FSA money exists for. At Mito, the Galleri multi-cancer early detection test is payable with an HSA or FSA card at checkout, the same as any other test.

Screening that follows a published guideline, your age, or a family history is also the easiest kind to explain if an administrator asks why you bought it.

Genetic and allergy testing

Genetic testing splits by purpose, and this is where the general health line bites hardest.

• Disease-risk and pharmacogenomic sequencing is diagnostic. It is testing for a medical reason, and it is HSA and FSA eligible. Mito’s whole genome sequencing and its shipping charge are payable with an HSA or FSA card.
• Ancestry and trait reports are not medical care. A test that tells you where your ancestors lived is not diagnosing, treating, or preventing disease. When a single product bundles both, only the medical portion has a case, and you need an itemized receipt that separates them.

Allergen-specific IgE blood panels are diagnostic lab tests and qualify on the same laboratory fee basis. See allergy test cost for what drives the price and what the results can and cannot tell you.

At-home test kits

A test kit collected at home is treated the same as a sample drawn at a patient service center. The IRS rule turns on the medical purpose of the test, not on who held the collection device. Publication 502 even lists a home pregnancy test kit by name as an includable expense. A finger-stick or saliva kit whose sample is analyzed by a certified laboratory is a laboratory fee.

Imaging and body composition scans

Diagnostic imaging ordered for a medical reason qualifies, including scans used to assess disease risk. A DEXA scan is a useful example of why purpose matters: a DEXA used to measure bone mineral density is osteoporosis screening and clearly medical, while the same machine used purely to report body fat percentage for fitness tracking is a weaker case. Describe what you bought accurately on the claim, and keep the itemized receipt.

Quick-reference eligibility table

Statuses here describe how the IRS rule generally applies. Your plan is still allowed to be stricter.

What usually is not eligible

Vitamins and supplements. Publication 502 excludes the cost of nutritional supplements, vitamins, and herbal supplements unless a medical practitioner recommends them as treatment for a specific medical condition diagnosed by a physician. Mito’s own payment rail enforces this: the checkout refuses to put a supplement on HSA or FSA funds, and the “Pay with HSA/FSA” option disappears when a supplement is in the cart. If you want both, order the lab test separately. See are vitamins and supplements HSA or FSA eligible for the full rule and when a letter of medical necessity changes it.

Purely cosmetic procedures and products. Publication 502 says you generally cannot include cosmetic surgery, with narrow exceptions for a congenital abnormality, a personal injury, or a disfiguring disease.

Testing with no medical purpose. Ancestry kits, trait reports, and novelty testing are not diagnosis, treatment, or prevention of disease.

Anything an insurer already paid for. A qualified medical expense is one that was not compensated by insurance or otherwise. You cannot reimburse yourself twice for the same bill.

Documentation and reimbursement

What an itemized receipt must show

An itemized receipt is the document your administrator actually wants, and it is different from an order confirmation or a credit card statement. It should show:

• the patient’s name;
• the provider or merchant name;
• the date of service or purchase;
• a description of each item, specific enough to identify the test; and
• the amount charged for each item.

Keep it even when nobody asks. For an HSA there is no reviewer at the time of purchase, so the receipt is what supports the withdrawal if the IRS ever questions it.

Auto-substantiation

Many health merchants are set up so that eligible items are substantiated automatically at the point of sale, which means the card transaction clears without you filing anything. Most Mito products are auto-substantiated through Flex, so a letter of medical necessity is usually not needed.

When a letter of medical necessity is requested

A letter of medical necessity, often shortened to LMN, is a note from a clinician connecting a specific purchase to your medical situation. Administrators ask for one when an item sits in a gray area, most often supplements or a broad panel with no obvious clinical trigger.

An LMN has to come from a clinician who has examined you and is involved in your care, usually your primary care physician. Mito does not issue LMNs for HSA or FSA reimbursement. Mito can supply a letter on Flex letterhead explaining the auto-substantiation, which is often what the administrator actually needed.

A physician order is not the same thing as an LMN, and it is not automatic proof. A lab test ordered through a direct-to-consumer platform like Mito comes with the test authorization already in place, which supports the medical purpose. The expense still has to meet the Publication 502 standard, and your plan still applies its own substantiation rules.

If a claim is denied

Ask the administrator which document or detail was missing, since a denial is often a paperwork problem rather than an eligibility ruling. Then decide whether to resubmit with a better itemized receipt, add an LMN, or accept the outcome. Remember that an employer’s FSA can exclude something the IRS would allow, so a denial does not always mean the expense failed the IRS test.

FSA timing across plan years

FSA claims generally have to be for expenses incurred during the plan year you were covered. Some administrators are more flexible about the exact timing, and most give a run-out window to submit claims for expenses already incurred. HSAs are different: you can reimburse yourself at any time, including years later, as long as you kept the receipt.

How to pay with HSA or FSA at Mito checkout

Mito accepts HSA and FSA cards directly through Flex, its HSA and FSA payments partner, so there is no separate claim to file for most purchases.

1. Add the tests to your cart and choose “Pay with HSA/FSA” at checkout.
2. Enter your HSA or FSA debit card on the Flex checkout page and finish as usual.
3. Watch for the receipt. Flex emails an itemized receipt from notifications@withflex.com, not from Mito. Search your inbox for “withflex” if you cannot find it.

A few specifics worth knowing before you get there:

• Declines are usually about funds. HSA and FSA cards are debit cards, and insufficient balance is the most common reason one is declined. Your administrator can confirm your balance.
• No card handy? Still choose “Pay with HSA/FSA”, then pay with a regular credit card. Flex emails the itemized receipt so you can submit it for reimbursement yourself.
• One HSA or FSA card per purchase. Splitting one order across two HSA or FSA cards is not supported. If one card does not cover the total, enter a credit card for the remainder.
• Sales tax rides along. Sales tax on eligible items is covered by HSA and FSA funds too.
• Every item has to be eligible. The HSA and FSA option is not offered when your cart contains a supplement, or one of the small number of individual products flagged ineligible. Put the eligible tests in their own order.

The Mito FAQ has the full HSA and FSA section, including what to do when an administrator asks for more documentation.

Are direct-to-consumer lab tests HSA or FSA eligible?

Yes, generally. Nothing in Publication 502 excludes a test because you bought it yourself instead of through a doctor’s office. The IRS asks what the expense was for, not which door you walked through. A direct-to-consumer lab test that runs real diagnostic assays in a certified laboratory is a laboratory fee that is part of medical care.

Three practical points make direct-to-consumer testing easier to defend:

1. The order exists. Direct-to-consumer lab tests, Mito’s included, come with the test authorization, so there is a clinical order behind the sample rather than a self-ordered purchase. That supports the medical purpose, without being a guarantee on its own.
2. The receipt is itemized. Because there is no insurance claim, the itemized receipt is the only record, which makes it worth keeping carefully.
3. Nothing is double-paid. Cash-pay testing is not billed to insurance, so the expense is not compensated for by insurance, which is one of the conditions in the definition.

The cases that still fail are the ones failing for everyone: ancestry reports, trait kits, and testing with no medical purpose.

Where Mito fits

Mito Health is a direct-to-consumer testing and membership service built around paying cash for lab work, which is the situation HSA and FSA funds are designed for.

• Membership is $9 a month, and that is where Mito makes its money, so members pay at our cost on tests. See membership for what it includes.
• More than 1,000 labs, scans, and kits are in the catalog, with transparent member pricing and no membership required to order.
• The Mito Essential Panel is $89.60 for members. That is the member price verified against the live catalog on 1 October 2026; panel prices are computed per state and per variant, so confirm the current price for you before ordering.
• More than 2,000 Quest, Labcorp, and BioReference draw locations are available for sample collection, or you can request an at-home blood draw.
• Every result is reviewed by a clinician, and members get trends and ongoing guidance between draws.

If you are comparing what you would otherwise pay, see how blood test prices compare and how to get lab tests without insurance. If you want to order without going through a doctor first, see how to order lab tests without a doctor.

Disclaimer

This guide is general information about how IRS rules on qualified medical expenses apply to health testing. It is not tax advice, not legal advice, and not a determination about your account or your employer’s plan. Eligibility for a specific purchase is decided by your HSA or FSA plan administrator, and an employer’s FSA may be stricter than the IRS rules described here. Figures and IRS guidance cited here were current as of October 2026 and change over time. Confirm with your administrator or a tax professional before relying on any of it.

References

1. Internal Revenue Service. Publication 502 (2025), Medical and Dental Expenses. What Are Medical Expenses; Laboratory Fees; Physical Examination; Pregnancy Test Kit; Cosmetic Surgery; Nutritional Supplements. https://www.irs.gov/publications/p502. Accessed October 2026.
2. Internal Revenue Service. Publication 969 (2025), Health Savings Accounts and Other Tax-Favored Health Plans. Qualified medical expenses; additional contribution at age 55 or older; additional 20% tax. https://www.irs.gov/publications/p969. Accessed October 2026.
3. Internal Revenue Service. Revenue Procedure 2025-19, 2026 inflation adjusted amounts for Health Savings Accounts. Internal Revenue Bulletin 2025-21. https://www.irs.gov/irb/2025-21_IRB. Accessed October 2026.
4. Internal Revenue Service. IRS releases tax inflation adjustments for tax year 2026. https://www.irs.gov/newsroom/irs-releases-tax-inflation-adjustments-for-tax-year-2026-including-amendments-from-the-one-big-beautiful-bill. Accessed October 2026.
5. Internal Revenue Service. Notice 2024-75, Preventive Care for Purposes of Qualifying as a High Deductible Health Plan. Internal Revenue Bulletin 2024-44. https://www.irs.gov/irb/2024-44_IRB. Accessed October 2026.

Frequently asked questions

Can I use my HSA for blood work?

Yes, in general. IRS Publication 502 lists laboratory fees that are part of medical care as a qualified medical expense, and that covers ordinary blood work such as a complete blood count, a comprehensive metabolic panel, a lipid panel, or an HbA1c. The money comes out of your HSA tax free as long as the expense meets that standard and no insurer has already paid for it. Keep the itemized receipt with your tax records.

Are at-home lab test kits HSA or FSA eligible?

Usually yes. The IRS does not treat a collection location as the deciding factor, so a finger-stick or saliva kit that runs a real diagnostic assay in a certified laboratory is treated the same way as a draw at a patient service center. Publication 502 also lists a home pregnancy test kit by name. The kits that run into trouble are the ones measuring something with no medical purpose, such as ancestry or trait reports.

Do I need a doctor's order to use HSA or FSA funds on a lab test?

Not as a separate step, and an order is not a guarantee on its own. A physician order supports the case that a test served a medical purpose, which is one of the things an administrator weighs. It does not by itself make an expense qualify: the expense still has to meet the Publication 502 definition of medical care and your plan still decides its own substantiation. Direct-to-consumer lab tests, including Mito's, already include the test authorization, so there is no separate requisition for you to arrange.

How much can I contribute to an HSA in 2026?

For calendar year 2026 the HSA contribution limit is $4,400 for self-only high deductible health plan coverage and $8,750 for family coverage, set by IRS Revenue Procedure 2025-19. If you are 55 or older at the end of the tax year, your limit increases by an additional $1,000. A health FSA is separate: the 2026 employee salary reduction limit is $3,400, with a maximum carryover of $680 where the plan allows one.

Can I use HSA or FSA funds to pay for someone else's lab test?

Yes, for the people the IRS covers, and the two accounts do not cover exactly the same people. For an HSA, Publication 969 lists you, your spouse, every dependent you claim, and anyone you could have claimed as a dependent except that they filed a joint return, had gross income at or above the exemption amount, or you could be claimed as someone else's dependent. That last test is why a parent you support can still qualify even though their income is too high to claim. A health FSA covers that same group and adds your child under age 27 at the end of the tax year, whether or not the child is your dependent, so an independent 25-year-old can be reimbursed from a health FSA but not from an HSA. Neither account covers a friend, and your plan can be narrower than the IRS rule.

What happens if I use HSA money on a test that does not qualify?

The withdrawal stops being tax free. Publication 969 says the part of a distribution not used for qualified medical expenses is included in your income, and there is an additional 20 percent tax on it. That extra tax does not apply after you turn 65, become disabled, or die. With a health FSA the mechanics differ: the claim is denied, or a card purchase has to be substantiated or repaid to the plan.

Can I pay part of an order with an HSA card and the rest with a credit card?

Yes at Mito, and this is the normal path when your balance does not cover the full amount. Pay with a single HSA or FSA card and enter a regular credit card on the Flex checkout page for the remainder. Splitting one purchase across two HSA or FSA cards is not supported. Flex emails an itemized receipt covering the order so you can claim the eligible portion.

Is a general wellness panel HSA eligible?

It depends on what the panel measures and why you bought it, and it is the least predictable category here. A broad panel made of diagnostic assays such as lipids, HbA1c, thyroid function, and kidney and liver markers is screening for conditions, which is squarely inside the Publication 502 definition of medical care. A panel bought purely out of curiosity, with no screening or monitoring purpose, is the case an administrator is most likely to question. Keep the itemized receipt, and ask your plan before you buy if the amount matters to you.