My health plan (Cigna) through my employer is a HDHP that comes with an HSA (through HSABank). When somebody in my family gets medical services, they "bill" the insurance, which tells the medical provider how much they think I should pay based on their contracts and my deductible, the health insurance applies that amount toward my deductible, and the medical provider bills me. The theory is that I contribute to the HSA via payroll deduction to be able to pay the deductible with pre-tax dollars, and get reimbursed from that account for the amount I pay the medical provider.
What I'm trying to wrap my head around is what happens when the amount the insurance company says to pay doesn't completely line up with the bill from the medical provider. Many medical providers have a "prompt pay discount", often for a significant portion of the bill (ranging from 10% to 30% in my experience, depending on the provider). So to try to make this concrete, if I go to the doctor, their contracted price with the insurance might be $100, and the Explanation of Benefits from the insurance says that they've applied $100 to the deductible, but the bill from the doctor would only be for $80 since it includes a line on the bill for a $20 "prompt pay discount". Do I get reimbursed from the HSA for the full $100 (of what the insurance deductible is), or for the $80 I actually paid?
My intuition is that it would only be the $80 actually paid, because that's the actual expense I'm incurring. But then I'm rather confused by the design of HSABank's web site. When Cigna processes a claim, it shows up in the list of expenses that can be reimbursed on HSABank's site. I can click on the expense and get reimbursed the amount of the insurance deductible very easily. But there's no way to tell it to reimburse me only a smaller amount. If I wanted to only get the amount paid, I need to jump through hoops like marking the expense as paid without a reimbursement (to get it to be cleared from the list of items I can get reimbursed for), and then add it back manually as a separate medical expense. It's convoluted enough that I think I might be missing something and I could get reimbursed for the full amount that was applied to the deductible, since this seems like a pretty typical scenario and I would expect a place literally called "HSA Bank" to know how this is supposed to work. It feels like either me or HSABank is missing something.