Comment by kstrauser

That's not the difference. The difference is that you have to have an HDHP to use an HSA. My employer pays for me to have a very good low-deductible policy. I did the math and it would almost certainly cost me more out of pocket to have an HDHP than what I have now. If you are young, single, and healthy, the equation may look different. If you're older and have a spouse and kids, it's shockingly easy to hit the deductible and OOP max year after year.

I could imagine a case where I'd start an FSA. An HSA did not work out well for me a few years ago when I tried it, and would be even less likely to be a win for me now.