The rating on the senior debt of Fannie Mae reflects the company's status as a government sponsored enterprise (GSE). While there is no U.S. government obligation to support Fannie Mae's obligations, the Secretary of the Treasury has authority to purchase up to $2.25 billion of Fannie Mae obligations, and the approval of the Secretary of the Treasury is necessary for the corporation's issuance of debt obligations and MBS. Fannie Mae is regulated by the Office of Federal Housing Enterprise Oversight, which is itself under the Department of Housing and Urban Development (HUD). Among the public purposes that Fannie Mae seeks to fulfill is the promotion of mortgage credit through increasing the liquidity of mortgages. This, in turn, facilitates home ownership
