@Derone Patterson: Your house does not have to be owned free and clear but it does have to pass an inspection. If they find any infractions you'll have a reasonable amount of time to get it corrected.
That said, I leased to a section 8 tenant for 3 yrs and ended up evicting her. Long story short, she made unapproved modifications to the property, almost burned my house down AND I later discovered she was cooking meth. I'll never go the section 8 route again. Maybe just a brush of bad luck but I've leased that property for almost 15 years and nobody even came close to being as bad a tenant as her and her children. She was the 1st and last section 8 tenant for my properties.