Affordable Housing Credit Improvement Act of 2017 This bill amends the Internal Revenue Code, with respect to the low-income housing credit, to rename the credit "the affordable housing credit" and make several modifications to the credit. The bill revises tenant eligibility requirements, with respect to: the average income test, income eligibility for rural projects, increased tenant income, student occupancy rules, and tenant voucher payments that are taken into account as rent. The bill revises various requirements to: establish a 4% minimum credit rate for certain projects, permit relocation costs to be taken into account as rehabilitation expenditures, repeal the qualified census tract population cap, require housing credit agencies to make certain determinations regarding community revitalization plans, prohibit local approval and contribution requirements, increase the credit for certain projects designated to serve extremely low-income households, increase the credit for certain bond-financed projects designated by state agencies, increase the population cap for difficult development areas, and eliminate the basis reduction for a property that receives the tax credit for investments in energy property if the affordable housing credit is allowed for the property. The bill also modifies requirements regarding the reconstruction or replacement period after a casualty loss, rights related to building purchases, the prohibition on claiming acquisition credits for properties placed in service in the previous 10 years, foreclosures, and projects that assist Native Americans.