The federal government channels much of its support for asset building through the tax code. Asset-building tax subsidies, primarily for homeownership and retirement saving, totaled $384 billion in 2013. This report reviews federal tax expenditures for housing, retirement, savings, business development, and higher education. We highlight research on the effectiveness of and justifications for these expenditures, find limited efficacy in their current form, and note possible adjustments. We estimate the distributional effect of major tax expenditures and find that the vast majority of subsidies benefit the top two income quintiles. Last, we review prospective policies such as matched saving accounts and automatic enrollment.