Per IRS Publication 502 Medical and Dental Expenses (Including the Health Coverage Tax Credit), page 2:

Introduction

Medical expenses include dental expenses, and in this publication the term “medical expenses” is often used to refer to medical and dental expenses.

Page 15:

Flexible Spending Arrangement

You can't include in medical expenses amounts for which you are fully reimbursed by your flexible spending arrangement if you contribute a part of your income on a pre-tax basis to pay for the qualified benefit.

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