<prompt> Human: I am a US resident and opted for a HSA account with my new job. Mad Fientist describes how it is beneficial take advantage of tax-free HSA investments growth withdrawals by holding off on medical bill reimbursements until post-retirement. The deadline to file claims for a HSA account for 2017 expenditures is March 15, 2018. When I login to PayFlex I see a list of my claims. I already made the payments to all the claims using money I had outside my HSA. Now my question is how does the system know that I made the payment so that I wont have issues when I go to withdraw come retirement? Do I simply save a stack of payment confirmations? Assistant: Are you certain you opted for an HSA and not an FSA? Because an FSA does have a submission deadline and is not the same thingHuman: Im 100 positive that I have a HSA account. HR put out the announcement explicitly stating that Employees enrolled in Health Savings Account HSA have until March 15, 2018 to incur eligible expenses that would be reimbursable from their 2017 plan year funds.  <response>: Your HR department is wrong then. That deadline only applies to FSAs, not HSAs. 