You'd be surprised by how many different kinds of expenses are covered under an HSA. Check out this list of eligible expenses.
In general, you can use your HSA to pay for any qualified medical expense. Qualified medical expenses are defined by the IRS and include medical care, vision and dental care expenses, prescription drugs, and payments for long term care services and insurance.
An HSA may reimburse certain types of insurance premiums, such as COBRA continuation, or any health insurance plan maintained while receiving unemployment compensation under federal or state law for the HSA holder or for his/her spouse or dependents. If you have an HSA and are age 65 or older (whether or not you’re entitled to Medicare), you may use your HSA to pay for any deductible health insurance, such as retiree medical coverage other than a Medicare supplemental policy.