A 15-year mortgage means you pay less interest - and you also have less opportunity to take advantage of the mortgage interest deduction. The Tax Cuts and Jobs Act, which is in effect from 2018 to 2025, allows most homeowners to deduct all of their mortgage interest payments for the year on home loans up to $750,000. But that deduction won’t do much for you unless you have other deductions to push you above the standard deduction.