A buy-down mortgage rate is a financing option where the borrower pays an upfront fee to the lender in exchange for a reduced interest rate for the initial years of the loan. This temporary reduction in interest helps lower the borrower’s monthly mortgage payments during the initial period. It’s a popular choice for homebuilders looking to incentivize buyers and make homeownership more affordable in the early years of homeownership. However, borrowers should carefully evaluate the long-term costs and benefits before opting for a buy-down mortgage.