Final answer:
Ginnie Mae is the mortgage-backed security that is directly backed by the U.S. government.
Step-by-step explanation:
Mortgage-backed securities are financial instruments created by bundling together a pool of mortgage loans and selling them to investors. These securities are categorized into different types, including government-backed and non-government-backed securities. The mortgage-backed security that is directly backed by the U.S. government is the Ginnie Mae (Government National Mortgage Association) security.
Ginnie Mae is a government-owned corporation that guarantees the timely payment of principal and interest to investors of mortgage-backed securities. It is responsible for guaranteeing securities backed by mortgages insured or guaranteed by the Federal Housing Administration (FHA), the Department of Veterans Affairs (VA), and the Department of Agriculture's Rural Housing Service (RHS).
Other types of mortgage-backed securities, such as those issued by Fannie Mae (Federal National Mortgage Association) and Freddie Mac (Federal Home Loan Mortgage Corporation), are not directly backed by the U.S. government. However, they have implicit government backing and are considered relatively safe investments because of the perception that the government would step in to prevent default in case of financial distress.