Agency The purchase of mortgage-backed securities (MBS) from government-sponsored enterprises (GSEs) like Fannie Mae, Freddie Mac, and Ginnie Mae, the latter of which is a wholly-owned government company, is known as MBS buying. The phrase is most often associated with the Federal Reserve’s (Fed) $1.25 trillion programs to acquire agency MBS, which began on Jan. 5, 2009, and ended on March 31, 2010, in order to ameliorate the impacts of the financial crisis of 2007–2008. During the COVID-19 crisis, the program was restarted on March 15, 2020.