Yes. You always have the option to choose when and when not to use your HSA dollars. You may pay for qualified medical expenses with after-tax dollars, allowing your HSA balance to grow tax-free. Many HSA participants elect to pay smaller expenses with after-tax dollars, allowing their balances to grow for the future. In fact, you can reimburse yourself at anytime in the future for eligible expenses you paid for using after-tax dollars as long as they were incurred while you had an open and funded HSA.