This legislation establishes new requirements for eligibility in key federal housing programs, mandating that mortgagors must be citizens of the United States to qualify. Specifically, it amends the National Housing Act to restrict eligibility for Federal Housing Administration (FHA) mortgage insurance solely to U.S. citizens. Furthermore, the bill imposes similar citizenship requirements on government-sponsored enterprises involved in the secondary mortgage market. It prohibits Fannie Mae and Freddie Mac from purchasing or securitizing conventional mortgages secured by one-to-four family dwelling units if the mortgagor is not a U.S. citizen. These provisions collectively aim to limit access to federally backed mortgage support and the broader housing finance system to U.S. citizens.