Itemized deductions

Itemized deductions are the line-by-line list on Schedule A. The categories are fixed by the IRS: medical and dental expenses above the AGI floor, state and local taxes paid (capped at $10,000), home mortgage interest, charitable contributions, and a small list of other categories like casualty losses in a federally declared disaster.

A household either itemizes on Schedule A or takes the standard deduction. Both reduce taxable income; only one of them is used on a given return. Whichever total is higher wins. Most households take the standard deduction because the categories on Schedule A do not add up to more than the flat amount, especially after the 2017 Tax Cuts and Jobs Act doubled the standard deduction.

Itemizing tends to make sense when one or more of the categories is large enough to clear the standard deduction on its own. A year with a mortgage and high state taxes. A year with a big charitable gift. A year with a major medical event that clears the AGI floor with room to spare. The gluten-free premium rarely tips a household into itemizing on its own; it usually contributes to a Schedule A total that is already large for other reasons.

The medical line is the only Schedule A category where the gluten-free premium has a home. Naming it on a different line would be wrong.

For the full Schedule A walkthrough, including when itemizing actually beats the standard deduction in a celiac household, read What Publication 502 actually says about celiac.