For years, taxpayers have been able to deduct home mortgage interest on their primary and second homes as an itemized deduction, subject to certain limitations. The interest deduction was limited to the interest on up to $1 million of acquisition debt and $100,000 of equity debt.
Acquisition debt is debt incurred to purchase, construct or substantially improve a taxpayer’s principal or second home. So when you purchased your home, that original loan was acquisition debt, and if you later borrowed additional money that you used to add a room, pool, etc., that loan was also acquisition debt. However, if the total of all of your acquisition loans exceeded the $1 million limit, then the interest on the excess debt over $1 million was not deductible as acquisition debt interest. Read more