GNMA or Ginnie Mae. A government-owned agency which buys mortgages from lending institutions, securitizes them, and then sells them to investors. Because the payments to investors are guaranteed by the full faith and credit of the U.S. Government, they return slightly less interest than other mortgage-backed securities. The agency guarantees three types of securities - Ginnie Mae I, a pool of similar mortgages with identical interest rates from one issuer, Ginnie Mae II, a pool of mortgages which can have different interest rates and/or multiple issuers, and Ginnie Mae REMICs, a pool of mortgage-backed securities.