Provisions vary. I looked at a place near Des Moines last month and they have two buy-in options. The higher one is 90% refundable, NOT contingent on reselling the unit, and applies when you leave the unit- death, move elsewhere, enter LTC. The lower IS amortized over a specified period- 2 years?- with no more due after that. They have LTC and that costs $13K/month. In between, they charge per service for additional things like help with medications, help bathing, or just having an attendant on an hourly basis (which gets expensive fast).
I prefer the larger buy-in because I want maximum flexibility. If things go downhill I want out without too much financial loss. If their LTC facility is full and they want to farm me out to a place 4 hours away (DS and family are in Des Moines) or it's a nightmare, I can go elsewhere.
Checking out another on Monday since I'm here visiting. This one has an indoor saltwater pool. I'm grateful I have options. News feed this morning (knowing my location) just showed an item on cases of neglect in some of the nursing homes in a couple of small towns in Iowa.