Can I pay for eligible expenses with after-tax dollars instead of using my HSA?

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.