How would Fidelity (who I have my HSA through) know that what I withdrew money for was actually a medical expense? And how does it get reported to count towards my deductible?
Generally, the HSA is self-reported. The bank/financial provider will allow you to withdraw/spend whatever you want from your HSA. They report to the IRS the total that you withdrew for the year (your gross distributions) on a 1099-SA form. At tax time, you use a form 8889 to report this number of your gross distributions, and how much of it was used for medical expenses. Ideally, all of it was used for medical expenses. If it was not all for medical expenses, there will be extra taxes/penalties due.
Different HSAs work differently, but for mine, which is held at a credit union, I can get money out several ways. I have an HSA checkbook and an HSA debit card that I can use anywhere. I can also transfer money out of my HSA into my regular checking account to reimburse myself for an expense, or even stop in at the teller window and take out cash. The credit union doesn't need to see any receipts for any of this. They don't care if I'm spending it at the doctor's office or the casino. It is up to me to make sure I'm spending the money in accordance to the law and that everything is reported correctly on my tax return.
Nothing is verified unless you get audited. You definitely should keep documentation on the expenses, because if you are audited, you need to be prepared to account for every withdrawal. Make sure you are very familiar with the rules on eligible medical expenses, so you know what is allowed and what is not. IRS Publication 502 has all the details on what is allowed.
As far as how it gets counted towards your deductible, you need to make sure that all of your medical bills get sent to your health insurance, even if you will eventually have to pay for it. For example, let's say you go to the doctor, and the bill is $150. Even if you know that the deductible is not met yet and you will be responsible for the entire $150, make sure the doctor's office submits the bill to your insurance. The insurance company will inform the doctor's office that you are responsible for all of it, but they will apply the amount towards your deductible.
Fidelity answers this pretty well:
- Do I need to keep my receipts?
Yes. The IRS requires that you keep your receipts for HSA account expenses. While you will receive an HSA bank account statement each month and you can access your account online, the receipts will be required should you ever be audited by the IRS. You may upload your receipts to the PilotHSA system for easy retrievel at a later date.