The short answer
The mmHg number determines eligibility:
| Compression Level | FSA Eligibility |
|---|---|
| 8-15 mmHg (mild) | Not eligible — LMN required |
| 15-20 mmHg (moderate) | Not eligible — LMN required |
| 20-30 mmHg (firm) | Not eligible — LMN required |
| 30-40 mmHg (extra firm) — always eligible | Eligible without LMN |
| 40-50 mmHg (RX strength) | Always eligible (often requires actual prescription anyway) |
That single number — printed on every legitimate compression product — is what determines whether you can swipe your FSA card.
Why the line is at 30 mmHg
SIGIS draws the line where compression products stop overlapping with consumer/athletic use. Below 30 mmHg, compression socks are widely used by:
- Runners for recovery
- Travelers on long flights
- People who stand all day at work
- General comfort wear
That overlap with non-medical use puts the lower compression levels into the dual-purpose category. A SIGIS classifier can’t tell whether someone bought 20-30 mmHg socks for a documented vein condition or for marathon training.
At 30-40 mmHg and above, the use case narrows considerably. This level of compression is uncomfortable for general wear and is almost exclusively used for treating diagnosed circulatory conditions: chronic venous insufficiency, lymphedema, post-thrombotic syndrome, post-surgical edema. The medical-only positioning is what triggers the always-eligible classification.
40-50 mmHg compression typically requires an actual prescription from a doctor regardless of FSA — it’s that strong.
How to check the mmHg level
Three places to look:
- The packaging — look for a number followed by “mmHg.” Reputable brands always print this.
- The product page — Amazon and FSA Store list compression level in the product specifications.
- The sock itself — many compression socks have the level woven or printed onto the sock.
If you can’t find a mmHg rating, it’s likely:
- Athletic compression (general fitness wear, no medical compression rating)
- Fashion compression (light support, typically 8-15 mmHg)
Either way, no rating = treat as not eligible without an LMN.
Brands that sell FSA-eligible (30-40 mmHg+) compression
Most major medical compression brands offer 30-40 mmHg lines:
- Jobst — UltraSheer, Relief, Opaque (medical-grade lines)
- Sigvaris — most lines including Cushioned Cotton, Style, Soft Opaque
- Mediven — Sheer & Soft, Comfort, Plus
- Truform — many sock and stocking variants
- Therafirm — Ease, Core-Spun
- Juzo — Soft, Dynamic, Basic
- Compression Solutions — graduated medical compression
- Vim & Vigr — has both lower-level (not eligible without LMN) and 30-40 mmHg medical lines
When shopping, filter for “30-40 mmHg” or “Class II / Class 2 compression” to ensure you’re getting the eligible level.
The LMN path for lower-level compression
If 30-40 mmHg is too strong (which is common — it’s clinical-grade), you can still buy 15-20 or 20-30 mmHg with FSA dollars by getting a Letter of Medical Necessity.
Conditions that typically support an LMN approval:
- Chronic venous insufficiency (CVI)
- Varicose veins (visible or symptomatic)
- Pregnancy-related leg swelling and varicosities
- History of deep vein thrombosis (DVT) — especially for travel
- Post-surgical recovery — particularly orthopedic surgeries
- Lymphedema (mild to moderate stages)
- Diabetic-related circulation issues
- Restless legs syndrome with documented venous component
- Prolonged immobility (bedrest, long-haul travel for work)
The LMN should come from a licensed provider (MD, DO, NP, PA), state the diagnosis, recommend the specific compression level, and document why it’s medically necessary. Submit it with your reimbursement request.
What about compression sleeves and other compression wear?
The same mmHg rule applies across the compression product family:
- Calf sleeves and leg sleeves — 30-40 mmHg+ medical sleeves are eligible; athletic recovery sleeves are not (without LMN)
- Arm sleeves for lymphedema — eligible at medical-grade compression with documented use
- Thigh-high stockings — same rule, mmHg level determines eligibility
- Pantyhose-style compression — 30-40 mmHg+ versions eligible
- Compression gloves — for arthritis or post-surgical lymphedema, generally need an LMN; not common in 30-40 mmHg ranges
Shopping for FSA-eligible compression
The cleanest path is to filter for 30-40 mmHg specifically. If you’re buying for general comfort and don’t have a documented condition, expect to pay out of pocket. If you do have a condition, get the LMN before buying lower-level compression and save yourself the reimbursement headache.
Compression products generally pair well with other first aid and medical supplies and pain relief items when building a bundle that fits your remaining balance.
Don’t let the balance go to waste
If you’ve been considering medical-grade compression for circulation, swelling, or post-surgical recovery, your FSA dollars cover the 30-40 mmHg range without paperwork. Use the balance tool to see how compression fits into your spend-down plan.