The
interest paid on a
loan securing one's primary residence. This excludes interest paid on
investment properties and most vacation homes. In the United States, one may reduce one's
taxable income by the amount one
pays in interest on all eligible
mortgages. There are some limits to the mortgage interest deduction. For example, one may only deduct interest on the first $1,000,000 worth of mortgages, aggregated with other home
debt. However, most homeowners can deduct all of their mortgage interest.