(I think?) 7 months, after which I owned it. Insurance covered some, I was on the hook for some of the monthly payment. I think I did the math at the beginning, and it ended up only being about 100 bucks cheaper to go through insurance than to buy one on my own (which is yet another example of how screwed up medical insurance is. If they were gonna pay x amount toward my CPAP, why didn't they just give me the option to buy it on my own, and reimburse me whatever they ended up paying the supplier? We'd've both ended up paying less! But I digress).

A short googling says S11 is $1004. Maybe figure out what you'd be on the hook for and how long if going through insurance. It might just be cheaper, or at least less hassle, to buy it on your own.

Don't plan on "only" needing it for a certain number of months. Choose whichever option lets you own it outright eventually. I've dropped a lot of weight since I got mine years back, so I may not NEED need it, but I still get better sleep with it than without.