Letter of Medical Necessity for Solar Generator: Free Template
By Lee Arnold
Medical Solar Power Backup Specialist | 8+ years in the field
Quick Answer:
A letter of medical necessity for a solar generator or portable power station needs five things: your diagnosis, the specific device you’re requesting, why it’s medically necessary, how long you’ll need it, and your licensed provider’s signature.
Below is a copy-paste template built on the structure of the official FSAFEDS LMN form, plus a script for actually asking your doctor for it — often the hardest part — and what to do if your HSA or FSA administrator denies the claim anyway.
This is a companion piece to our broader HSA-eligible portable power station guide, which explains eligibility rules in depth. This one is just the document and the process.
Table of Contents
A Letter of Medical Necessity Template You Can Copy
Most letter templates online are generic. This one is built directly on the field structure of the official FSAFEDS LMN form, adapted for backup power equipment. Copy it, fill in the brackets, and bring it to your provider.
[Provider Letterhead or Printed Name/Practice Info]
Date: [Date]
RE: Letter of Medical Necessity
Patient Name: [Patient Full Name]
Date of Birth: [DOB]
Diagnosis: [Medical condition — e.g., "reliance on home oxygen concentrator
for chronic respiratory insufficiency" or "insulin-dependent diabetes
requiring refrigerated medication storage"]
Medical Equipment Requiring Continuous Power: [Device — e.g., CPAP machine,
portable oxygen concentrator, home dialysis equipment, insulin refrigeration]
Requested Item: A portable power station / solar generator to provide
backup electrical power for the above medical equipment during power
interruptions.
Medical Necessity Statement: [Patient Name] depends on the above medical
device for [ongoing treatment / life-sustaining function]. Interruption of
electrical power poses a direct risk to this patient's health. A backup
power source is medically necessary to ensure continuous operation of
this equipment during a power outage.
Expected Duration of Need: [Duration — e.g., "ongoing" or "lifetime" for
a chronic condition]
Provider Name: [Printed Name]
Provider Signature: _____________________
License/NPI Number: [Number]
Date: [Date]A few notes on filling it in: your provider fills in the diagnosis and signs it — you shouldn’t write that part yourself. The “expected duration” field matters more than people think. A chronic, ongoing condition should say so explicitly, since it can save you from re-filing the letter every year.
How to Actually Ask Your Doctor for This
This is the step most guides skip, and it’s usually the real obstacle. Providers write dozens of letters a week and don’t always know what an HSA or FSA administrator needs to see.
Make it easy for them. Bring the template above already filled in with your device and diagnosis — leave only the medical necessity statement and signature for your provider to review and sign. Most providers will adjust the wording rather than write from scratch, which takes minutes instead of a full appointment.
During a regular visit, say directly: “I need a letter of medical necessity for my HSA/FSA to cover a backup power source for my [device]. I brought a template — could you review and sign it?” Being specific saves back-and-forth.
Some practices charge a small administrative fee for letters like this. Ask when you call to schedule, so it isn’t a surprise.
Filing It With Your HSA or FSA Administrator
Once you have the signed letter, most administrators want it submitted alongside — not instead of — your actual purchase receipt. Check your specific administrator’s portal for their claim form, since the process varies by provider (FSAFEDS, HealthEquity, WageWorks, and others each have their own submission steps).
Keep a copy of everything: the signed letter, the itemized receipt, and the claim confirmation. If a claim gets questioned or audited later, this is the paper trail that protects you.
If Your Claim Gets Denied Anyway
Even a complete, properly signed letter doesn’t guarantee approval on the first try — claims get kicked back for missing details or administrator-specific formatting fairly often. Don’t assume a denial is final.
FSAFEDS, the federal employee FSA program, publishes one of the more detailed public appeals processes, and it’s a useful model for what to expect even if your plan isn’t FSAFEDS specifically:
- Informal appeal — call your benefits counselor within 30 days to ask what was missing.
- First-level written appeal — submit a written explanation plus supporting documents (your LMN, receipt, itemized bill) within 60 days.
- Second-level written appeal — if still denied, a formal appeals committee reviews it within 30 days.
- Independent third-party review — a final, binding review outside the administrator itself.
Your own plan’s exact steps and deadlines will differ — check your administrator’s specific appeals policy — but the shape is usually similar: ask what’s missing, resubmit with more documentation, and escalate in writing if needed before giving up.
How This Differs From Our HSA Eligibility Guide
Our HSA-eligible portable power station guide covers the bigger picture: what IRS Publication 502 actually says, HSA versus FSA versus HRA differences, which power stations qualify, and common mistakes that get claims rejected.
This guide is narrower on purpose — it’s the document itself, a script for getting your provider to sign it, and what to do if the claim still gets denied. Read that guide first if you’re not sure you qualify at all; use this one once you’re ready to actually get the letter written.
FAQs
Does a letter of medical necessity guarantee my solar generator purchase gets reimbursed?
No. It’s a required piece of documentation, not a guarantee. Your administrator still reviews the full claim, and claims can be denied for reasons unrelated to the letter itself, like missing receipts or formatting issues.
Can my doctor charge me for writing this letter?
Some practices do charge a small administrative fee, since it takes provider time outside a standard visit. Ask when scheduling so it isn’t a surprise, and factor it in — it’s typically far less than the cost of the equipment itself.
How long is a letter of medical necessity valid?
It depends on your administrator, but many treat a letter for a chronic, ongoing condition as valid indefinitely if it says so explicitly, while others require annual renewal. State the expected duration clearly on the letter and ask your administrator directly if you’re unsure.
What if my doctor doesn’t want to write “medically necessary” for a backup power source?
Bring the specific medical reasoning — that your equipment (CPAP, oxygen concentrator, insulin refrigeration) requires continuous power and an interruption creates real health risk. Most providers are comfortable signing once the connection between the device and your condition is made explicit in writing.
Where do I actually submit this letter once it’s signed?
Through your HSA or FSA administrator’s claim portal or form, alongside your purchase receipt — not instead of it. Check your specific administrator’s process, since submission steps vary between providers like FSAFEDS, HealthEquity, and others.
Bottom Line
A letter of medical necessity for a solar generator doesn’t need to be complicated: diagnosis, device, medical necessity statement, expected duration, and a signature. The template above gives you a starting point built on an actual federal LMN form’s structure, not a generic form pulled from nowhere.
Bring it to your provider already filled in, submit it with your receipt, and if it gets denied, don’t assume that’s the end. Most administrators have a real appeals process, and missing paperwork is a fixable problem, not a dead end.
This article reflects the official FSAFEDS Letter of Medical Necessity form and FSAFEDS appeals process documentation current as of October 2026. HSA/FSA administrators set their own specific requirements and deadlines — confirm current details directly with your plan administrator before submitting a claim. This is not tax or legal advice; consult a tax professional for guidance specific to your situation.
