What is Fixed-Rate Mortgage?

A fixed-rate mortgage is a home loan structured with an interest rate that is established at closing and remains completely constant throughout the entire lifespan of the loan. As a result, the monthly principal and interest payment is guaranteed to stay the same from the first payment to the last, insulating the borrower from market interest rate volatility and economic inflation. Although the principal and interest portion remains locked, a borrower’s total monthly housing payment (often structured as PITI) may still fluctuate if there are changes in local property tax assessments or homeowner's insurance premiums held in the loan's escrow account.

Predictability and risk mitigation make the fixed-rate mortgage the most popular choice for homebuyers in the United States, typically offered in standard amortization terms of 15 or 30 years. A 30-year fixed-rate mortgage offers lower monthly payments but results in a higher interest rate and significantly higher cumulative lifetime interest costs. Conversely, a 15-year fixed-rate mortgage features a lower interest rate and pays off the principal twice as fast, but requires larger monthly payments. The primary disadvantage of a fixed-rate loan is that the rate does not automatically decrease when market interest rates fall; to capture lower rates, borrowers must refinance the loan, which requires paying new closing and origination costs.