At a glance
| Situation | HSA/FSA |
|---|---|
| Multivitamin, omega-3 or probiotics taken for general health | No |
| Blood test shows vitamin D deficiency → doctor recommends vitamin D | Yes, with an LMN |
| Iron-deficiency anemia diagnosed → doctor recommends iron | Yes, with an LMN |
| Prenatal vitamins your doctor recommends during pregnancy | Yes, with an LMN (some plan administrators allow them without one) |
| Over-the-counter medicines like cold medicine, pain relievers and allergy pills | Yes (no prescription needed since 2020) |
What are an HSA and an FSA?
Both are accounts that let you pay medical costs with pre-tax money. Spend the same 100 dollars and you save the amount you would have paid in tax.
| HSA | FSA | |
|---|---|---|
| Who | People on a high-deductible health plan (HDHP) | When your employer offers one |
| 2026 contribution limit | Self-only $4,400 · Family $8,750 (age 55+: add $1,000) | $3,400 |
| Leftover money | Keeps rolling over and stays yours if you change jobs | Usually must be spent within the year |
That's why many people wonder, "Can I spend my leftover FSA money on supplements?" Check the rules below first.
Why don't most supplements qualify?
The IRS medical expense rules (Publication 502) treat supplements, vitamins and herbal products as "things you take to stay generally healthy" and leave them out of medical expenses. There is one exception:
- To treat a specific condition diagnosed by a doctor
- When a medical professional recommends that supplement
Both must be true. So supplements you take "because I'm tired," "for my immune system" or "because I'm getting older" don't qualify.
When it works: diagnosis + Letter of Medical Necessity (LMN)
These are common cases where you can get an LMN and pay with your HSA or FSA.
| Diagnosis | Supplement |
|---|---|
| Vitamin D deficiency (blood test) | Vitamin D |
| Iron-deficiency anemia | Iron |
| Vitamin B12 deficiency | Vitamin B12 |
| Pregnancy | Prenatal multivitamin, Folate |
| Osteoporosis | Calcium · Vitamin D |
How to get a Letter of Medical Necessity (LMN)
An LMN (Letter of Medical Necessity) is a letter from your doctor confirming that "this supplement is needed for treatment."
- Ask your doctor (primary care provider): "I'd like to buy this with my HSA (or FSA). Could you write me an LMN?"
- The letter should include: the diagnosis · the supplement name and dose · how long to take it · the doctor's signature and license information.
- Many HSA/FSA administrators have their own LMN form on their website. Give that form to your doctor and it goes faster.
- An LMN is usually valid only for a set period (often 1 year). The period varies by administrator.
How to pay
- Pay directly with your HSA/FSA card: Products marked "FSA or HSA eligible" on Amazon and other stores can be paid for with the card right away. Most supplements don't have this label, so the payment may be declined, or you may be asked for proof later even if it goes through.
- Pay out of pocket, then get paid back: Buy with a regular card, then upload your receipt and LMN to your administrator for reimbursement. For supplements, this is the most reliable way.
What happens if you use it the wrong way?
- HSA: If you spend it on something that isn't a medical expense, that amount is hit with income tax + an extra 20% tax (if you're under 65). It can cause problems when you file your taxes later.
- FSA: Your administrator will ask for proof. If you can't provide it, your card may be suspended or you may have to pay the money back.
Don't assume "the card went through, so it's fine." A payment going through and a cost counting as a medical expense are two different things.
This may change
In May 2026, the Dietary Supplements Access Act was introduced in the US Senate. If it passes, starting in 2027 you could buy supplements with an HSA or FSA without an LMN (up to $250 a year for individuals, $500 a year for couples).
But it's still in committee and has not passed. For now, the rules above still apply. We'll update this page as soon as anything changes.
Summary
- Supplements just for general health → No
- Diagnosed deficiency or condition + doctor's recommendation → Yes, with a Letter of Medical Necessity (LMN)
- Paying first and getting reimbursed is the most reliable method. Keep your LMN and receipts
- Leftover FSA money is safer spent on over-the-counter items (pain relievers, allergy medicine, bandages, etc.) instead of supplements
Related supplements
Frequently asked questions
Does a multivitamin qualify if I have an LMN?
It can, if your doctor recommends it to treat a specific diagnosis (for example, a deficiency caused by an absorption problem). A multivitamin taken just "for your health" is hard to get an LMN for and doesn't qualify.
Do prenatal vitamins qualify without an LMN?
It depends on your administrator. Some accept them without an LMN and some require one. Look for prenatal vitamins on your administrator's list of eligible expenses.
What about fish oil?
Regular fish oil supplements need an LMN. Prescription omega-3 medicine that a doctor prescribes for high triglycerides is a prescription drug, so it qualifies right away.
Once I have an LMN, can I get reimbursed for supplements I already bought?
Usually only purchases made after the date on the LMN count. Get the LMN before you buy. Rules vary by administrator, so check yours.
Sources
Last updated 2026-10-15