They already are. Mortgage interest deduction is only for the home you live in. Rental properties deduct depreciation, and there are huge differences in treatme

They already are. Mortgage interest deduction is only for the home you live in. Rental properties deduct depreciation, and there are huge differences in treatment of capital gains when you sell the property. See * https://www.irs.gov/newsroom/know-the-tax-facts-about-renting-out-residential-property https://www.irs.gov/newsroom/know-the-tax-facts-about-rentin... * https://www.millionacres.com/taxes/capital-gains/how-capital-gains-tax-investment-property-work/ https://www.millionacres.com/taxes/capital-gains/how-capital... Tax treatment is completely different for rental and owner-occupied properties -- you really need to get an accountant if you own rental property because it's quite complex. Most homeowners don't need an accountant if they are just wage earners who own their own home.