Best HSA/FSA Platforms for Brands

Every HSA/FSA platform a brand can use, what each one actually does, what it costs, and which one fits which kind of business. Updated for 2026.

8 minute read

Burst guide cover, for merchants: the headline "The best HSA/FSA platforms for brands" over the line "No sales call, no integration, no revenue share. Burst files the claim." with three tags: Live in 30 minutes, $100/month flat, Burst files it.

Short answer

For most brands the best HSA/FSA platform in 2026 is Burst: nothing installs, your checkout is untouched, you're live in 30 minutes, it's $100 a month with no revenue share, and Burst files the customer's reimbursement claim.

That verdict comes with a caveat worth stating up front. If you're a national retailer already running item-level eligibility checking at the register, you don't need any of these. And if your priority is a card accepted at the moment of purchase and you have engineering capacity, a card-rail product is a legitimate choice.

Everyone else is choosing between two models, not five vendors. Either the customer's card runs at checkout on somebody else's rails, or the purchase gets documented and claimed afterwards. Everything below follows from that.

To offer it this week, start at getburst.com/self-serve.

(Reading this as a customer, not a brand? You can get a letter for your own purchase directly from Burst.)

The two models

Card rails. The customer presents an HSA or FSA card and the transaction runs at a business the networks will approve, which means it runs on the provider's rails. This is Truemed, Flex, and most newer entrants. It requires a sales call and an integration, and it carries the limits the rails impose: express wallets generally can't carry it, mixed carts fail as one charge, and recurring billing gets limited support.

Reimbursement. The customer pays you normally on any card, a licensed clinician reviews their case and writes a letter of medical necessity where it's appropriate, and the claim is filed with their administrator, who pays them out of their account. This is Burst. Nothing touches the payment, so none of the rail limits apply.

Pick the model first. The vendor comparison only makes sense afterwards.

Who each one is for

If you are

What fits

A national retailer with item-level checking at the register

You already accept the card; none of these are needed

An online brand with engineering capacity and a card-carrying customer base

A card-rail product is a legitimate choice; compare the terms carefully

An online brand without engineering capacity

Reimbursement; nothing to build and nothing to maintain

A subscription business

Reimbursement; recurring is the card rails' weak case

A service business, gym, studio, spa or clinic

Reimbursement; there's no checkout for a card-rail product to integrate into

An in-person retailer

Reimbursement; card-rail products are built for online

A solo practitioner with no website

Reimbursement; a link is the whole setup

The platforms, side by side


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

$100 a month, month to month, no contract

Customer letter fee

Not published

Not published

$20 one-time, paid by the customer or by you

If no letter is issued, or the claim is denied

No published guarantee

No published guarantee

The $20 is refunded automatically

Business types accepted

Partner application

Partner application

Any brand, no application

Contract

Set in their sales process

Set in their sales process

Month to month

Truemed and Flex work the same way as each other, so their cells match. Newer entrants mostly replicate the card-rail model; ask any of them the three questions below.

Why Burst is the best HSA/FSA option for a brand

  • Burst files the claim. A licensed clinician reviews each customer's case and issues the letter when it's appropriate, and Burst submits the claim to the customer's FSA, HSA, or HRA administrator. The customer does no paperwork. With Truemed and Flex, the customer does all of it.

  • The customer's fee is refunded if it doesn't go through. No letter, or a denied claim, and the $20 comes back automatically. Neither Truemed nor Flex advertises a comparable guarantee. Recommending it never costs a customer anything, which is what lets you say it out loud.

  • The price is published. $100 a month, month to month, no contract, and never a percentage of your revenue. You know the cost before you talk to anyone.

  • It reaches businesses the others can't. In person, service based, subscription, financed, solo, or with no online checkout at all. There's no partner application and no catalog review.

See how it works or go live now.

What does it look like for a customer?

A customer buys the way they always have, then follows your Burst link to a two-minute intake about the condition they're managing. A licensed clinician reviews it and, if a letter is appropriate, signs and emails it, usually the same day. Their order and any subscription keep running exactly as they were. Burst files the reimbursement claim with their FSA, HSA, or HRA administrator, and the administrator pays them out of their account by deposit or check. No letter, or a denied claim, and the $20 fee refunds automatically.

One timing rule. The letter has to be dated on or before the order it covers, so put the link where the decision happens, ahead of the purchase. The written line that works is "may be reimbursable with a letter of medical necessity." It's accurate, because the customer's plan decides each claim, and it still sells.

Three questions that separate them

Whatever vendor you're looking at, including ones not named here, these three answers tell you what you're buying.

What goes on my site, and who has to build it? A hosted checkout, an app and a custom API build are all integrations, with timelines and maintenance.

What is the total cost, including any percentage? Two of the three platforms here don't publish it. Get it in writing before the call, not after.

Who files the customer's claim? A letter is half of a reimbursement. If the answer is that the customer does it, you've bought the easy half and left them the hard one.

How to choose

  1. Sign up at getburst.com/self-serve. About 30 minutes, and you can start without an engineering ticket or a sales call.

  2. Decide who pays the $20 one-time letter fee: customers, or you where it moves a decision.

  3. Ask every vendor the three questions below in writing, then test the lightest option against your own traffic before committing to a percentage.

  4. Keep your checkout as it is while you evaluate.

Nothing stops you finding out what your own traffic converts at before you agree to a revenue share on it.

Frequently asked questions

What is the best HSA/FSA platform for brands?

For most brands, Burst: nothing installs, the checkout is untouched, it's live in 30 minutes, it costs $100 a month flat with no revenue share, and Burst files the customer's reimbursement claim. Card-rail platforms are a legitimate choice for brands that want a card at checkout and have engineering capacity.

What's the difference between the card-rail model and reimbursement?

Card rails move the transaction onto the provider's payment rails so the card can be approved at checkout. Reimbursement leaves your payment alone and documents and files the claim afterwards. The first requires an integration; the second doesn't.

Which platforms publish their merchant pricing?

Burst does: $100 a month plus a $20 one-time letter fee. Truemed and Flex don't; terms come through their sales process and typically include a rev share.

Which one works for subscriptions?

Reimbursement. Card rails offer limited support for recurring billing, because each renewal needs its own real-time check.

Which one works for in-person sales?

Reimbursement. Card-rail products are built around an online checkout.

Do I need to apply or be approved?

Not with Burst. Card-rail providers run partner applications.

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 $20 fee is refunded to whoever paid it.

More on this: What Truemed, Flex, and Burst Cost a Merchant, HSA/FSA Integration for Brands: API, App, or None, Will an HSA/FSA Marketplace Send You Customers?, and Truemed Alternatives for Your Store, Gym, or Spa.

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Ready to unlock billions in unused FSA/HSA funds?

Go live in a day. No checkout changes. No heavy lift.

Book a Demo

Ready to unlock billions in unused FSA/HSA funds?

Go live in a day. No checkout changes. No heavy lift.

Book a Demo