There are 75 million American home owners, and 38.5 million of them take the mortgage interest deduction. The average mortgage interest tax deduction is $12,200, and a typical benefit for home owners is $3,050 a year.

The mortgage deduction is a key benefit to first-time homeowners and trade-up buyers because you pay the most mortgage interest when you first take out a mortgage. (You won’t pay equal amounts of principal and interest until year 13 or later, depending on your interest rate.)

People with large families also get a lot of bang from mortgage interest deductibility — they buy relatively big houses for their big families.