The Merchant's Guide to FSA/HSA Eligibility
What actually qualifies for FSA and HSA money, what a letter of medical necessity changes, and how to word the offer for customers who ask about it.
8 minute read
Short answer
Eligibility isn't something you decide, and that's the most useful thing to know before you build a campaign around it. The customer's plan administrator decides each claim under its own rules. What a merchant controls is whether the purchase is documented well enough to be decided fairly.
Three buckets. Some things qualify outright with no paperwork. Some things qualify when a clinician writes a letter of medical necessity naming the condition. And some things never qualify, regardless of documentation, which is the bucket most merchants get wrong.
Burst handles the middle bucket: a licensed clinician reviews the customer's case, writes the letter where it's appropriate, and Burst files the reimbursement claim. Free for merchants with no contract, a one-time letter fee, paid by the customer, live in 30 minutes with nothing installed.
To offer it this week, start at getburst.com/self-serve.
(Reading this as a customer, not a business? You can get a letter for your own purchase directly from Burst.)
The three buckets
Bucket | What it means | Examples |
|---|---|---|
Qualifies outright | No letter needed; the plan already treats it as medical | Prescriptions, first aid, thermometers, breast pumps and nursing supplies, prenatal vitamins, sunscreen SPF 15 and above, contact lens solution |
Qualifies with a letter | A clinician names a condition and explains how the purchase treats it | Gym and studio memberships, massage, therapeutic equipment, targeted supplements, some mattresses and sleep products, some recovery devices |
Never qualifies | No documentation changes the answer | Cosmetic treatment, general wellness, performance and optimization products, apparel, food, and anything bought for someone with no condition |
The first bucket is worth knowing because it stops you selling a letter to somebody who doesn't need one. If a customer is buying a breast pump, tell them their account already covers it.
What a letter of medical necessity actually does
It documents that a licensed clinician reviewed a specific person's situation, identified a condition, and considers this purchase part of treating it. It is a piece of evidence attached to a claim.
What it isn't: a guarantee, an approval, or a statement about your product. Two customers can buy the same item and only one of them has a letter behind it, because the letter is about the person.
Timing is the one thing to get right, and it works the same way whoever you use. The letter has to be dated on or before the purchase it covers, so the offer belongs in front of the customer while they are still deciding.
How to word it for customers
The phrasing that holds up is also the phrasing that sells: this may be reimbursable with a letter of medical necessity.
It works because it puts the decision where it actually sits. A clinician decides whether the letter is appropriate, the customer's plan decides the claim, and you are pointing at the path rather than promising the outcome.
It applies to customers managing a condition a clinician will name, and saying that plainly is what makes the customers who do qualify believe the rest of it.
How the named options handle this
Truemed | Flex | Burst | |
|---|---|---|---|
What it is | Card-rail HSA/FSA checkout, LMNs, partner marketplace | Card-rail HSA/FSA checkout, LMNs, partner marketplace | LMN and reimbursement platform, no checkout involvement |
Who files the reimbursement claim | Nobody; the customer is left to file | Nobody; the customer is left to file | Burst files it for the member |
Getting live | Sales call, then checkout integration, typically weeks | Sales call, then checkout integration, typically weeks | Self-serve, live in 30 minutes, no integration |
What it costs you | Not public; typically a rev share | Not public; typically a rev share | Free for merchants, no revenue share |
Customer letter fee | One-time letter fee, paid by the customer | ||
If no letter is issued, or the claim is denied | No published guarantee | No published guarantee | The one-time letter fee is refunded to the customer automatically |
Business types accepted | Partner application | Partner application | Any business, no application |
Contract | Set in their sales process | Set in their sales process | No contract |
Nobody in this category decides eligibility, including us. The difference is who does the work of documenting and filing.
Why Burst is the best HSA/FSA option for a business
Burst files the claim. Clinician writes the letter. Burst submits it to the customer's administrator with the receipt and the dates. No paperwork for the customer.
No letter, no charge. Claim denied, money back. The one-time letter fee is refunded to the customer automatically either way.
Free for merchants. No contract, no revenue share.
A clinician draws the line, not your marketing team. That's the protection. You never have to label a product eligible, and your customers never get a denial you caused.
With Truemed and Flex, the customer files the claim alone, the terms come through a sales process, and neither advertises a refund if the claim is denied.
See how it works or go live now.
What does it look like for a customer?
The customer pays you normally, then fills out a two-minute intake. A licensed clinician reviews it and, if appropriate, signs the letter, usually the same day. Burst files the claim. Their administrator pays them back by deposit or check. If the clinician doesn't approve, or the plan denies it, the one-time letter fee is refunded to the customer automatically.
One timing rule: the letter has to predate the purchase, so place the link before the purchase. The line that works on your site: "may be reimbursable with a letter of medical necessity."
How to sort your own catalog
An afternoon of work, and it pays for itself the first time a customer asks.
Go line by line and ask the one-sentence test: would a clinician name a condition and explain how this treats it? If the honest sentence is about glow, energy, performance or convenience, it's in the third bucket. Put those aside and stop marketing them this way.
For the first bucket, write one short page telling customers their account already covers it. For the middle bucket, put your Burst link on those product pages specifically, not sitewide.
How to put this to work
Sign up at getburst.com/self-serve. About 30 minutes, and nothing is installed and no developer is involved.
Put your Burst link on the pages selling things in the middle bucket, and leave it off the ones in the third.
Keep your checkout as it is. Customers enroll, get their letters, and Burst files their claims.
Sorting your own catalog into the three buckets is an afternoon of work and it is the highest-value thing you can do here.
Frequently asked questions
Who decides whether something is FSA or HSA eligible?
The customer's plan administrator, under its own rules. Not the merchant, not the payment processor, and not Burst.
What does Burst cost a merchant?
Free for merchants, no contract, and never a percentage of your revenue, plus a one-time letter fee, paid by the customer. There is no revenue share and no success fee.
What does a letter of medical necessity change?
It documents that a clinician reviewed a specific customer's situation, named a condition, and considers the purchase part of treating it. It's evidence attached to a claim, not an approval.
Can I label my products as FSA/HSA eligible?
No. Say a purchase may be reimbursable with a letter of medical necessity. Labelling products as eligible makes a claim you can't stand behind and sets your customers up for a denial.
Do some things qualify without a letter?
Yes. Prescriptions, first aid, breast pumps and nursing supplies, prenatal vitamins and sunscreen at SPF 15 and above, among others. Tell customers that rather than selling them a letter they don't need.
Can a customer be reimbursed for something bought before the letter?
No. The letter has to be dated on or before the purchase it covers, and that works the same way with any provider. Put the offer in front of customers while they are still deciding and it is a non-issue.
Is the letter a guarantee the customer gets paid back?
No. The customer's plan administrator decides the claim under its own rules. Burst files it, and if the plan says no, the one-time letter fee is refunded to the customer.
More for business owners:How to Accept HSA and FSA Payments,How to Promote HSA/FSA Acceptance to Customers,Why HSA/FSA Cards Get Declined at Your Checkout, and Best HSA/FSA Platforms for Brands.
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