What counts as proof of a medical expense
Updated 14 August 2026 · Reviewed against IRS Publication 502 (2025)
A reimbursement you take in 2046 rests on paperwork you filed in 2026. Four facts have to survive that gap: who was treated, what the care was, what it cost, and that you paid it.
The four facts
A record substantiates an expense when it establishes all four:
- The patient. You, your spouse, or a dependent.
- The date of service. When the care happened, which is not always when you paid for it.
- The nature of the care. Enough to place it in a Publication 502 category. “Office visit” or “prescription” is usually enough; a diagnosis is not required.
- The amount you paid out of pocket, after insurance.
The documents that carry them
An itemized receipt from the provider carries most of the four on its own. An explanation of benefits from the insurer carries the date, the provider, and the amount left to you, but rarely proof that you paid. A card statement or bank record proves payment but says almost nothing about the care. Two documents together usually beat one.
Keep the original rather than a summary. A portal’s “year-end statement” is a convenience the portal can withdraw; the receipt it was built from is the record.
What decays, and how fast
- Provider portals close, or migrate and drop history, when a practice is acquired.
- Card statements go back six or seven years at most.
- Thermal receipts from a pharmacy counter fade to blank in a few years in a drawer.
- Email receipts survive as long as the account does, which is not the same as forever.
None of this is a problem in the year the care happens. All of it is a problem in the year you finally decide to reimburse yourself.
What HSA Proof stores
The captured image or PDF, unaltered, plus the fields read from it and confirmed by you: patient, date, provider, amount, and category. It fingerprints every original with SHA-256 when it is saved, and the export includes those hashes, so anyone can confirm later that the file has not changed since the day you filed it.
HSA Proof does not decide whether a document satisfies the IRS. It records what you have and when you had it.