Left on autopilot, a refinance resets you to a fresh 30 years, but you can ask for a custom term that keeps your original payoff date. A refinance is a brand-new loan that pays off the old one, so a fresh 30-year term is the default. Lenders can also write custom terms down to the exact month you have remaining: three years into a 30-year, you can refinance into a 27-year, or even an odd term like 332 months, and lose none of the progress you've made. Ask your loan officer to run it both ways, because the choice has a real cost. Stretching back to a full 30 years drops the monthly payment the most, but it can cost more over the life of the loan, since you've handed back years of amortization and are paying interest longer. A shorter custom term keeps your timeline and usually wins on total interest, at a higher monthly payment. Resetting to a new 30 can be a valid choice if you're deliberately going for the lowest possible payment and you understand the trade. The mistake is letting the reset happen by default. The honest comparison is biggest monthly savings versus biggest total-cost savings, and the sweet spot is usually enough rate improvement that you keep your original payoff date and still lower the payment. Any good loan officer should show you both numbers before you sign, so ask for them.