Thousands of Floridian families in need of affordable housing rely on privately-owned multifamily rental apartments that were constructed under federal government programs in the 1960s through 1980s. The terms of the subsidy programs and the age of the structures now cause many units to be faced with a high risk of loss to the affordable housing stock. Units are lost as a result of conversion to market-rate housing upon the prepayment or maturity of a subsidized mortgage, or the expiration of a rental assistance contract or use restriction. Units are also lost through physical deterioration and mortgage default. Preservation of affordable housing has been hampered by a lack of multifamily housing research and data. This paper describes the creation of an assisted housing inventory and the analysis of property characteristics as an approach to identify properties most at risk of loss and to steer preservation policy and funding. This risk assessment approach is applied to Florida’s assisted housing stock. For units at risk by 2015, it found that the majority receives project-based rental assistance, that all population groups are impacted by the potential loss, that almost half have non-profit ownership, and that only four counties house almost 50 percent of atrisk units. Rent restructuring, debt restructuring, additional funding programs and property tax relief are described as preservation strategies.