IRC § 213

IRC § 213 is the Internal Revenue Code section that defines which medical expenses count on Schedule A. It is the statute behind the medical-and-dental line. Publication 502 is the IRS's plain-language walkthrough of the same material.

Two subsections do the heavy lifting. Subsection (a) sets the AGI floor: the medical line counts only the portion of eligible expenses above 7.5 percent of AGI. Subsection (d) defines what counts as a medical expense; the definition is broader than most readers expect, and includes "amounts paid for the diagnosis, cure, mitigation, treatment, or prevention of disease, or for the purpose of affecting any structure or function of the body."

The gluten-free premium fits into the (d) definition through the special-diet route. A medically prescribed diet that treats a disease (celiac, in this case) is treatment under the statute. The increment over the cost of an ordinary diet is the medical expense, per Revenue Ruling 55-261 and IRS Information Letter 2011-0035.

IRC § 213 also contains the rules on whose expenses count (the taxpayer, the spouse, dependents), the rules on reimbursement (insurance and HSA distributions reduce what counts), and the rules on the medical-mileage rate (set annually; 20.5 cents per mile in 2026, per medical mileage).

The statute itself is rarely cited in everyday tax-prep conversation; CPAs and tax professionals work from Publication 502, which is the same material in plain language. But § 213 is the underlying authority when a question gets specific enough that the booklet does not answer it cleanly.

For the full walkthrough, read What Publication 502 actually says about celiac.