Affordable Housing Investment Act of 2008 - Amends the Internal Revenue Code to revise and enhance tax incentives for investment in affordable housing, including by: (1) renaming the low-income housing tax credit as the affordable housing credit; (2) revising the applicable percentage rates for such credit; (3) increasing the amount of such credit for low-income buildings that are part of state-designated projects; (4) revising rules for the treatment of scattered site and rural residential rental housing projects; (5) permitting affordable housing credits for federally-assisted moderate rehabilitation developments; (6) allowing an offset against alternative minimum tax liability for affordable housing tax credit amounts; (7) exempting interest on certain exempt private activity bonds, qualified mortgage revenue bonds, qualified veterans' mortgage bonds, and certain exempt facility bonds used for residential rental projects from the alternative minimum tax; and (8) allowing the use of mortgage revenue bonds to provide housing assistance for disaster victims, single parents, and displaced homemakers.
Repeals: (1) rules requiring recapture of income from sales of low-income buildings that are reasonably expected to be operated on a low-income basis; and (2) requirements to use repayments of mortgage revenue bonds for redemptions.
Directs the Secretary of the Treasury to modify regulations for the low-income housing tax credit to disregard certain housing assistance grants for purposes of making reductions in the basis of property eligible for such credit.