If you only have rental income and it is not subject to social security tax, how do you pay in to your social security?
I have had 11 rentals for the past 4 years for my income.
Rental income can be counted for Social Security if you report it as self-employment income AND if you provide "services for the conveniences of the occupants"–i.e., room service, making beds, furnishing linens and towels, providing laundry service, preparing and serving meals, sweeping and mopping floors, dusting and cleaning, washing dishes, cleaning bathroom fixtures, emptying wastebaskets and picking up and replacing scattered or misplaced articles.
See SocSec web site:
http://www.ssa.gov/OP_Home/handbook/handbook.12/handbook-1218.html
If you only collect rent, this is passive income reported on Schedule E and is not eligible for Social Security payments or benefits.