USDA loans are guaranteed by the U.S. Department of Agriculture's Rural Development program. They're designed to make homeownership accessible in eligible rural and suburban areas — which actually cover about 97% of U.S. land area, including many suburbs of major cities.
The signature benefit is zero down payment. There are also no PMI requirements (USDA uses a smaller guarantee fee instead) and competitive 30-year fixed rates. Income limits apply: typically up to 115% of the area median household income.
USDA loans require the home to be in an eligible area (check the USDA eligibility map) and the borrower to be income-eligible. Credit minimums are typically 640, though some lenders go lower with manual underwriting.