You may be able to write off all mortgage interest on a second home if you’re not renting it out for extended periods. Getty Images By Kimberly Lankford, Contributing Editor August 9, 2017 QI’m about to buy a lake house as a second home. I plan to go there a few times a month but not live there full-time, and I don’t plan to rent it out. Is the mortgage interest tax-deductible?SEE ALSO: Dreaming of a Vacation Home In Retirement? Here's a Reality Check AYes. As long as you don’t rent out a second home for more than 14 days each year, you can deduct the mortgage interest you pay on it. But your deduction is capped at the interest you pay on up to $1 million of debt on your first and second homes combined. You can also deduct property taxes on your first and second home. All of these deductions are only available if you itemize. If you change your mind about renting the lake house to others, you’ll still be able to deduct the mortgage interest as long as you don’t lease it out for more than two weeks a year. And any rental income you receive will be tax-free, too, if you stay within the two-week limit. SEE ALSO: 10 Dream Waterfront Vacation Homes If you rent out the house for longer than that, you’ll have to report the rental income to the IRS. But you can still deduct some of the mortgage interest and rental expenses, such as insurance and utilities, for the portion of the time that you rent out the house. Calculating the deduction gets complicated because you’ll need to determine how much of those costs should be allocated to when you were leasing out the house and when you were personally using it. Advertisement For more information about deducting mortgage interest on second homes and the rules for deducting rental expenses, see Tax Planning for Owning a Second Home and Buying a Vacation Home. Also see IRS Publication 530, Tax Information for Homeowners. SEE ALSO: How Smart a Home BUYER Are You? Got a question? Ask Kim at email@example.com.