If I Exchange a Product, Can I Still Use My LMN for HSA/FSA Reimbursement?

If you used an HSA or FSA to get reimbursed for a product and later need to exchange it, you may be wondering whether your Letter of Medical Necessity (LMN) still applies or whether you’ll need to go through the process again. Here’s what you need to know.

Usually, yes—if the new product serves a similar purpose as the original one.
Your LMN is valid for one year and can be used for products that support the same health need it was originally written for.

However, if the product you're exchanging for is different in purpose from the original, you'll need to complete a new eligibility survey so your provider can determine whether a new LMN is needed.

Example: If your original product supported joint health and you exchanged it for something meant to support digestion, that’s a different use case and may require a new LMN.

That depends on how the exchange was handled:

• If the product you received in the exchange cost the same:
  You can usually submit your updated receipt along with your original LMN—no need to restart the process.

• If the new product costs more:
  Your HSA/FSA provider may ask for documentation to show that the higher-priced item is not just an “upgrade” but still medically necessary. You may also need to submit a short explanation of the exchange.

• If the new product costs less and you were already reimbursed:
  You may need to return the difference to your HSA/FSA account or report it as a non-qualified expense during tax time. Check with your HSA/FSA provider for instructions.

If you’re exchanging a product after already starting or completing the reimbursement process, it’s helpful to keep:

• Your original receipt

• Any refund or exchange confirmation from the brand

• A new receipt showing what you received in the exchange

• A short note explaining the reason for the exchange (just a few sentences)

• An updated LMN if the new product is for a different health use

If you’re unsure whether your LMN still applies or if your new product is eligible, the best thing to do is retake the eligibility survey. It only takes a few minutes and ensures you have the right documentation to support your reimbursement.