Under IRS Section 213(d), an HSA or FSA expense qualifies when it's used to diagnose, treat, mitigate, cure, or prevent a medical condition.

That includes more than most people think. For qualified customers, fitness equipment, supplements, red light therapy tools, and similar interventions may qualify when supported by a Letter of Medical Necessity (LMN).

An LMN is issued by an independent licensed practitioner who determines a product is an appropriate intervention for a diagnosed condition. It's what reclassifies a consumer product as a qualified medical expense.

The product doesn't change. The documentation does.