Changes have been made in the rules for deducting qualified residential interest, i.e., interest on your home mortgage, under the Tax Cuts and Jobs Act (TCJA). Under the pre-Act rules, you could deduct interest on up to a total of $1 million of mortgage debt used to acquire your principal residence and a second home, i.e., acquisition debt. For a married taxpayer filing separately, the limit was $500,000. You could also deduct interest on home equity debt, i.e., debt secured by the qualifying homes. Qualifying home equity debt was limited to the lesser of $100,000 ($50,000 for a married taxpayer filing separately), or the taxpayer's equity in the home or homes (the excess of the value of the home over the acquisition debt). The funds obtained via a home equity loan did not have to be used to acquire or improve the homes. So you could use home equity debt to pay for education, travel, health care, etc. Under the TCJA, starting in 2018, the limit on qualifying acquisition debt is reduced to $750,000 ($375,000 for a married taxpayer filing separately). However, for acquisition debt incurred before Dec. 15, 2017, the higher pre-Act limit applies. The higher pre-Act limit