The mortgage interest on a second home which you use as a residence for some portion of the taxable year, is generally deductible if the interest satisfies the same requirements for deductibility as interest on a primary residence. Real estate taxes paid on your primary and second residence are, generally, deductible. Deductible real estate taxes include any state, local, or foreign taxes on real property levied for the general public welfare. Deductible real estate taxes do not include taxes charged for local benefits and improvements that increase the value of the property. For more information, refer to Publication 17, Your Federal Income Tax for Individuals, Chapter 24; Tax Topic 503, Deductible Taxes; and Publication 530, Tax Information for First-Time Home Owners.

References:

• Publication 936, Home Mortgage Interest Deduction
• Publication 530, Tax Information for First-Time Homeowners
• Publication 17, Your Federal Income Tax for Individuals
• Tax Topic 503, Deductible Taxes
• Tax Topic 505, Interest Expense

Source: www.irs.gov