Ginnie Mae

The Government National Mortgage Association, colloquially known as Ginnie Mae, is a U.S. government owned corporation whose chief function is to guarantee mortgage-backed securities (MBS) made up of loans from approved issuers. It guarantees the timely payment of the principal and interest. Lenders are thus able to obtain a good price for their loans in the secondary market and use the proceeds to provide new loans.

See also: http://www.ginniemae.gov/