The Federal National Mortgage Association (FNMA) (NYSE: FNM), commonly known as Fannie Mae, is a government sponsored enterprise (GSE) of the United States government. As a GSE, it is a shareholder-owned corporation authorized to make loans and loan guarantees. It is not backed or funded by the U.S. government, nor do the securities it issues benefit from any explicit government guarantee or protection.

This secondary mortgage market helps to replenish the supply of lendable money for mortgages and ensures that money continues to be available for new home purchases. The name "Fannie Mae" is a creative acronym of the company's full name that has been adopted officially for ease of identification.