My mom lives in the in-law suite we added to our home. Mom got the cash for us to build the suite by taking out a mortgage on her existing home and using that home as security, but we make the payments. Our accountant told us that we can deduct the mortgage interest because my mom is 82, claimed as a dependent on my tax return, and not making enough money to file taxes. May we deduct the interest? ... Log in to view full article.