10 Health Treatments You Can Get Covered by your FSA/HSA with a Letter of Medical Necessity (and How Much You’ll Save)

Created by Christopher Caffrey, ACNP, PMHNP

March 6th, 2025

You know what’s frustrating? Spending your hard-earned, post-tax dollars on health treatments that your FSA or HSA could be covering—if only you knew the loophole.

Most people think these accounts only cover the basics: doctor visits, prescriptions, and maybe a bottle of ibuprofen if you’re lucky. But the reality? Your FSA/HSA can cover way more—if you get a Letter of Medical Necessity (LMN). A quick online health evaluation using Flexup Wellness will turn "non-eligible" into "eligible."

With an LMN, you can turn “nope, not covered” into “hell yes, covered”—saving you 30% on health treatments that would otherwise drain your wallet.

Here are 10 surprising treatments you can hack into eligibility with an LMN, their average costs, and how much average savings in Massachusetts. LMN's are good for 12 months!

These are examples and hypothetical examples; not medical advice. Do I really need to say that...yes I do.

1. Therapeutic Mattress

Out-of-pocket: ~$4,000

FSA/HSA Savings (30%): ~$1,200

If your back feels like it belongs to an 80-year-old, a therapeutic mattress could be a game-changer. The catch? FSA/HSA doesn’t cover it unless you have a note from a licensed medical practitioner stating that your spine needs the upgrade.

2. Massage Therapy

Out-of-pocket: $100 per session ($2,500/year for regular visits)

FSA/HSA Savings (30%): ~$750

Regular massages for relaxation? Not covered.Massages for chronic pain, injury recovery, or tension headaches? Covered with an LMN.

3. Gym Membership

Out-of-pocket: ~$600/year

FSA/HSA Savings (30%): ~$180

If your doctor recommends exercise as a treatment for obesity, diabetes, or hypertension, your gym membership can be covered. Just make sure you get that LMN first. Coverage starts the day you receive it and not retroactive.

4. Personal Trainer

Out-of-pocket: $75 per session ($3,000/year for regular training)

FSA/HSA Savings (30%): ~$900

A personal trainer for general fitness? No-go.A trainer for rehab, weight management, or a chronic condition? That’s an FSA/HSA-approved hack.

5. Air Purifier

Out-of-pocket: ~$250

FSA/HSA Savings (30%): ~$75

If you have severe allergies or asthma, a doctor can write an LMN proving you need an air purifier to breathe like a functional human.

6. Standing Desk

Out-of-pocket: ~$400

FSA/HSA Savings (30%): ~$120

Sitting all day is terrible for you. If you have back pain, sciatica, or other spinal issues, a standing desk can be covered using services like Flexup Wellness.

7. Home Sauna

Out-of-pocket: ~$3,000

FSA/HSA Savings (30%): ~$900

Saunas aren’t just luxury items; they help with muscle recovery, circulation, chronic pain, and even mental health. With an LMN, you can ditch the spa memberships and get your own covered.

8. Cold Plunge Bath

Out-of-pocket: ~$250

FSA/HSA Savings (30%): ~$75

Cold therapy is clinically backed for reducing inflammation, boosting metabolism, and aiding in recovery. If you have chronic pain or inflammation, your FSA/HSA can help you freeze yourself in style. Wear a winter hat!

9. Red Light Therapy

Out-of-pocket: ~$1,000

FSA/HSA Savings (30%): ~$300

Red light therapy has been shown to reduce inflammation, speed up wound healing, and even improve joint pain. If deemed eligible and cleared by your PCP, your FSA/HSA can cover it.

10. Supplements (with a medical need, aka LMN)

Athletic Greens (AG1 or other green supplement)

Packed with vitamins, minerals, probiotics, and adaptogens, AG1 green supplements support gut health, immune function, and energy levels by filling in nutritional gaps and promoting overall well-being.

Out-of-pocket: $99/month ($1,188/year)

FSA/HSA Savings (30%): ~$356.40

Mushroom Coffee (MudWtr or others)

Combining medicinal mushrooms like lion’s mane and chaga with coffee or tea alternatives, mushroom coffee supports cognitive function, reduces stress, acts as an anti inflammatory and provides sustained energy without the jitters of regular coffee.

Out-of-pocket: $40/month ($480/year)

FSA/HSA Savings (30%): ~$144

Colostrum

Rich in immune-boosting antibodies, growth factors, and nutrients, colostrum enhances gut health, supports immune function, and may aid in muscle recovery and inflammation reduction.

Out-of-pocket: $50/month ($600/year)

FSA/HSA Savings (30%): ~$180

Glutamine

A key amino acid for gut and muscle health, glutamine helps repair the intestinal lining, supports immune function, and aids in muscle recovery, making it beneficial for athletes and those with gut issues.

Out-of-pocket: $30/month ($360/year)

FSA/HSA Savings (30%): ~$108

Omega-3s

Essential fatty acids found in fish oil and algae, omega-3s support brain health, reduce inflammation, improve heart health, and may help with mood regulation and joint function. High EPA and DHA Content – At least 1,000–2,000 mg of combined EPA and DHA per serving for optimal brain, heart, and anti-inflammatory benefits. Ensure the brand is molecularly distilled and sourced from small, cold-water fish like sardines and anchovies to ensure they are free from heavy metals and contaminants.

Out-of-pocket: $30/month ($360/year)

FSA/HSA Savings (30%): ~$108

Probiotic (Seed - $90/month)

Designed for optimal gut health, high-quality probiotics like Seed contain 24 clinically studied strains that support digestion, immune function, and microbiome balance while improving nutrient absorption and reducing bloating. Dual capsule technology prevents microbes from dying from stomach acid.

Out-of-pocket: $60/month ~$1,080/year

FSA/HSA Savings (30%): ~$324

High-Quality Multivitamin (O.N.E. by Pure Encapsulations)

Providing bioavailable forms of essential vitamins and minerals, this multivitamin supports energy production, cognitive function, immune health, and overall well-being without unnecessary fillers.

Out-of-pocket: $18/month ($216/year)

FSA/HSA Savings (30%): ~$64.80

Melatonin

A natural sleep hormone that helps regulate the body’s sleep-wake cycle, making it effective for improving sleep quality, reducing jet lag, and supporting those with insomnia or shift work schedules. Unlike sedatives, it promotes natural sleep without dependency and can also support immune function and antioxidant defense.

Out-of-pocket: $10/month ($120/year)

FSA/HSA Savings: ~ $36

Magnesium Glycinate

Known for its high absorption and gentle effect on digestion, making it ideal for reducing stress, improving sleep, and supporting muscle and nerve function without causing laxative effects. It is often recommended for anxiety, migraines, and muscle relaxation due to its calming properties.

Out-of-pocket: 25$/month ($300/year)

FSA/HSA Savings (30%): ~ $90

Collagen

Promotes healthy skin, joints, hair, and gut health by providing essential amino acids that support tissue repair and elasticity. It can improve skin hydration, reduce wrinkles, and strengthen bones and connective tissues.

Out-of-pocket: $40 per container ($320/year)

FSA/HSA Savings (30%): ~$96

They pile up faster than your Amazon cart on payday.

How Much Could You Actually Save?

Let’s say you’re interested in:

• Gym Membership ($600)

• Probiotic (Seed - $1,080/year)

• Athletic Greens ($1,188/year)

• Air Purifier ($250)

  
  

That’s $3,118 in out-of-pocket expenses.

With an average tax savings of ~30%, you’d save $935.40 just by using your FSA/HSA.

Final Thoughts: Don’t Leave Money on the Table

Most people are burning post-tax dollars on health treatments when they don’t have to. The IRS isn’t going to tell you what’s eligible—you have to know the game.

That’s where FlexUp Wellness comes in. They provide up to 3 Letters of Medical Necessity per their HIPAA secure health evaluation to help you maximize your FSA/HSA. Stop wasting money, and get more treatments covered...and it only takes 2 mins of your time and 47 bucks!

Hope this helps! Check out the other great blogs on FlexUp Wellness for more insights.