Hospitalization Lifestyle isn't a lifestyle you choose like Street, Squatter, Low, Middle, High, and Luxury. It's intended to represent the costs for extended hospitalization-- If something puts you in a hospital for several days, that's how much it costs you. 500¥ every day, or 1000¥ every day for intensive care (like if you almost died in an explosion, for instance). You do pay per day, not per month like normal lifestyles. Strictly speaking it might not be an actual hospital, as the book says it could be "a real one, a clinic equipped as a hospital, or a private location with the necessary equipment".
The "bonus" for this would be that your GM should be making a Medicine roll for you every day to represent the hospital's staff working to help you get better. The dice pool is up to the GM, but should be based on the area the hospital is in and how much funding the hospital probably has. A the back room of a local Street Doc in a crappy part of town might roll 8 dice, where a fancy hospital in Bellevue could be rolling 16+. There's no hard rules for it.
This is all from page 369-370 of the core book.
