As government-sponsored enterprises (GSEs), Fannie Mae and Freddie Mac are hybrids: created and chartered by Congress for specific public policy purposes, they are nonetheless private, profit-seeking businesses whose shares are traded on the New York Stock Exchange. Their "government-sponsored" nature confers certain advantages over their purely private competitors. As a result, their operations have expanded rapidly over the years and they long ago assumed and continue to play critical roles in the residential mortgage market. This book provides background on the GSE reform issue, summarizes the provisions of H.R. 1427 and S. 1100, and compares them to legislation passed by the House in the 109th Congress.