Why fish oil qualifies for HSA/FSA reimbursement
Fish oil isn't eligible just for being fish oil; it needs a medical recommendation behind it. A Letter of Medical Necessity (LMN) documents why a medical practitioner recommends the supplement for a specific health condition.
Under “Nutritional Supplements,” IRS Publication 502 counts supplements as medical expenses when they are recommended by a medical practitioner as treatment for a specific medical condition diagnosed by a physician.
Your LMN is that written recommendation. Over-the-counter fish oil is an omega-3 supplement, so it qualifies through your letter.
For the broader category, see our vitamins and supplements eligibility guide.
Does fish oil work?
Yes, for specific uses, especially bringing down high triglycerides. Mayo Clinic’s fish oil review says fish oil supplements reduce triglycerides and modestly lower blood pressure.
EPA and DHA are the omega-3 fats found in fish and seafood. The NIH explains their roles in cell membranes, blood vessels and the immune system. The findings below show why a practitioner might recommend them for a specific condition.
What conditions can support a fish oil LMN?
High triglycerides, rheumatoid arthritis, hypertension, major depression and painful periods are a few common conditions a provider can tie fish oil to, each with evidence behind omega-3 use. Your letter ties the fish oil you buy to your own condition.
- High triglycerides. A systematic review of 47 trials found that fish oil lowered fasting triglycerides in people with high blood fats.
- Rheumatoid arthritis. Omega-3 supplementation reduced the number of tender joints in a meta-analysis of 18 randomized trials involving 1,018 people with rheumatoid arthritis.
- High blood pressure. Mayo Clinic reports modest blood-pressure reductions among people taking fish oil supplements, with some evidence of a greater effect in moderate to severe high blood pressure.
- Depression. International Society for Nutritional Psychiatry Research guidance includes pure EPA or EPA-rich omega-3 formulations in clinical care for major depressive disorder.
- Painful periods. A systematic review of omega-3 supplementation for dysmenorrhea, the medical name for painful periods, pulled together 12 studies and 881 women. Pooling eight of them for pain, it found less menstrual pain after supplementation.
Have a different condition? Fish oil qualifies the same way once a provider ties it to any other health condition of yours.
How to get a Letter of Medical Necessity for fish oil
You can get a Letter of Medical Necessity for fish oil in two ways:
- Through Crates, typically in under 24 hours. Complete a 2–3 minute online health assessment about your condition and the fish oil you take. A licensed provider reviews it, and if you qualify, your LMN is issued. Each letter covers 12 months and renews each year.
- Through your own doctor, a few days to a few weeks. Book a visit, say you want to use HSA/FSA funds for fish oil, and ask them to document how it helps manage your condition. Check for a signature and date on the letter. A visit can involve a copay.
How to buy fish oil with HSA/FSA funds
You can keep shopping at the retailer you already use, then get your money back.
- Get your LMN first. Go through Crates or your own doctor before your next fish oil purchase.
- Buy your fish oil anywhere. Pay with a personal card, online or in store, and save an itemized receipt showing the product, purchase date and amount paid.
- Get your funds back. With Crates one-click reimbursement, we file the claim for you. Or you can upload the letter and receipt yourself. For an HSA, pay yourself back and keep both with your tax records.
Already bought fish oil? It's still fine to get a letter now. What you can file is set by your account dates and the letter, and having it before your next bottle makes that claim simple. Our HSA and FSA guide explains the account differences.
Which fish oil and omega-3 supplements qualify?
Fish oil, cod liver oil and krill oil all qualify with an LMN. The NIH lists these as omega-3 supplement sources, alongside algal oil.
| Supplement type | What it is | HSA/FSA eligibility |
|---|---|---|
| Fish oil and concentrated omega-3 supplements | Oil from fatty fish, with EPA and DHA | Yes, with an LMN |
| Cod liver oil | Oil from cod liver, as a liquid or capsules | Yes, with an LMN |
| Krill oil | Oil from krill, small ocean crustaceans | Yes, with an LMN |
The same letter rule applies to every brand. If you are buying vitamin D separately, our vitamin D eligibility guide covers that purchase.
How much can you save on fish oil?
Take fish oil every day? Those savings stack up, since HSA/FSA funds can cut up to 30% from the real cost. IRS Publication 969 explains the tax advantages of these accounts. The examples below use sample yearly totals, so you can hold them up against your own receipts.
Each column multiplies the purchase price by the illustrated tax rate:
| Annual fish oil spending | Estimated savings at 20% | Estimated savings at 30% |
|---|---|---|
| $120 | $24 | $36 |
| $240 | $48 | $72 |
| $360 | $72 | $108 |
| $600 | $120 | $180 |
Say you spend $30 a month: that's $360 a year. Figure about 30% in combined taxes and you save $108 that way, which brings your real cost down to $252. The combined rate reflects federal, state and payroll taxes where applicable; your savings depend on your tax situation and how you fund the account.
The retailer still charges the full purchase price. The money you get back comes from your own HSA or FSA; the savings are the taxes you didn't pay. Any cost for obtaining your LMN is separate from these examples.
