Truemed vs. Dr. B vs. MedSlip: Letter of Medical Necessity Services Compared (2026)

Adam Z. Kawalek, MD

July 7, 2026 · 5 min read

Full disclosure before anything else: MedSlip is my service, so you should read this the way you would read any comparison written by one of the players. What I can promise is this: every factual claim below comes from each company's own public pages, checked in July 2026, and where a competitor is genuinely better for your situation, I say so. All three of these services are legitimate. They are built differently, and the differences decide which one fits you.

The three services at a glance

Now the honest read on each.

Truemed: built into the brands you buy from

Truemed is the category giant, and its core idea is genuinely clever: instead of you going to get a letter, the letter process comes to you at checkout. Thousands of health and fitness merchants have Truemed integrated, you complete a clinical intake survey as part of the purchase, an independent licensed clinician reviews it, and their published figure is that 90% of letters are issued within 7 hours. There is no direct charge to you as the consumer. If you are buying equipment or a membership from a brand that has Truemed built in, it is the smoothest experience in the category, full stop.

The structural limit is the same thing that makes it smooth: per their own help center, Truemed issues letters specifically for purchases made through their partner merchant network. If your gym, your trainer, or your massage therapist is not a partner, that is generally outside their standard flow. Truemed is a checkout layer more than it is a doctor you visit.

Dr. B: the lowest-price letter

Dr. B is a telehealth company that added HSA/FSA letters to a broader visit menu, and its headline advantage is price: the fitness Letter of Medical Necessity consult is $19 as of July 2026. The intake is AI-assisted, a licensed provider reviews it, and their published turnaround is within one day, often within hours. Unlike Truemed, the letter comes to you, so it works for your own purchases wherever you made them. If your priority is the least expensive legitimate path to a letter, Dr. B is the price leader and it is not close.

What you trade at that price is mostly depth and specificity of the relationship: it is a high-volume telehealth flow, and the provider who reviews your intake is whoever is on that day. For many people, that trade is completely fine.

MedSlip: the named-physician letter

MedSlip is the smallest and most focused of the three: Letters of Medical Necessity are the entire product. Two honest cons first. At $69 it is the most expensive letter here, and there is no checkout integration; you submit the letter to your administrator yourself (our reimbursement guide walks through it).

What the $69 buys is specific. Every request is reviewed by the same person: me, a board-certified internal medicine physician, and my name, NPI, and state license are printed on every letter I sign. Letters carry a QR code and document ID that anyone, including your plan administrator, can verify online. Review is usually same day, you are only charged if a letter is actually issued, and because the letter comes to you, it works for the gym you already belong to, the trainer you already use, or the equipment you bought anywhere. If an administrator ever questions your claim, "a named physician you can look up, on a letter you can verify" is the strongest position to be standing in.

Which one is right for you

• Buying from a brand with Truemed at checkout, like a piece of equipment or a partnered program? Use Truemed. It is free to you and built into the purchase.
• Want the cheapest legitimate letter for your own purchases? Use Dr. B at $19.
• Want a named, verifiable physician letter for a gym, trainer, or purchase you chose yourself, reviewed the same day? That is what MedSlip is for.

These are not mutually exclusive. Plenty of people get equipment through a Truemed checkout and a letter for their own gym separately. Fit the tool to the purchase.

What to check no matter which you choose

The same rules bind all three services, because they come from the IRS, not from any of us. You need a genuine diagnosed condition; a letter cannot make a general-wellness purchase medical, and the IRS warned in 2024 about companies suggesting otherwise. Your administrator always has the final say; no service can guarantee reimbursement, and you should be wary of any that implies it. And whichever letter you get, keep it with your receipts; that pair is your documentation if a claim is ever reviewed. If you are still working out what can qualify at all, start with the eligibility catalog or the plain-English LMN guide.

Prices, turnaround figures, and features above are from each company's public pages as of July 2026 and can change. If you spot something outdated, tell us at support@medslip.co and we will correct it.

This article is for general information and is not medical, tax, or legal advice. Confirm plan specifics with your HSA or FSA administrator.

Adam Z. Kawalek, MD

Board-Certified Physician · Founder, MedSlip · Cedars-Sinai · Johns Hopkins

Dr. Kawalek is a board-certified internal medicine physician with 15+ years of clinical experience. He founded MedSlip to give patients fast, affordable access to the Letters of Medical Necessity that make fitness and wellness spending HSA/FSA-eligible.