Substantiation

Substantiation is the paper trail a CPA or tax professional expects on the medical-expense line of Schedule A. For a celiac household claiming the gluten-free premium, the chain is three documents: the diagnosis, the prescribed-diet instruction, and the receipts.

The diagnosis is usually the pathology report from the biopsy that confirmed celiac, plus the blood-test results that led to the biopsy. Some households also have a written diagnosis letter from the gastroenterologist who interpreted the results. Either form works; what matters is that the diagnosis is a documented medical record from a clinician, not self-reported.

The prescribed-diet instruction is the clinical letter or chart note from the diagnosing physician saying the patient must follow a gluten-free diet. Without this link the chain has a gap; the diagnosis alone does not establish that the diet is a medical treatment in the eyes of the IRS.

The receipts are the third link. This is the part Gluten Hero is built to produce cleanly. Each logged item carries a date, a store, a GF premium calculation (or full price for GF-Only items), and the GF and regular prices that produced it. The year-end report rolls them up into a single PDF the household can hand to a CPA or tax professional.

What the chain is meant to do is survive a future IRS review. Most returns are not reviewed; the substantiation is the answer if one is. A reviewer asks "where does this medical-expense number come from," and the chain answers in three pieces: the medical condition, the medical instruction, and the records.

The professional-judgment piece is in how much of each link the household keeps and how it is organized. Gluten Hero handles the third link; the household handles the first two.

For the underlying source material, read What Publication 502 actually says about celiac.