My wife and I each own a home and want to file married this year. Do we need to designate one home as our primary residence for mortgage interest deduction purposes?

[Opus 17]

You can deduct mortgage interest on your main home and one second home, up to a combined indebtedness of $750,000.   So you shouldn't have a problem.  (The regulations say your main home is where you live most of the time, so it sort of designates itself, unless you have separate living arrangements.  But since you can deduct interest on two homes, it should not be an issue.)

[DianeW777 · Accepted solution]

No.  You are allowed to use mortgage interest from your main home and your second home.

Generally, home mortgage interest is any interest you pay on a loan secured by your home (main home or a second home). The loan may be a mortgage to buy your home, or a second mortgage.

You can deduct home mortgage interest on the first $750,000 ($375,000 if married filing separately) of indebtedness. However, higher limitations ($1 million ($500,000 if married filing separately)) apply if you are deducting mortgage interest from indebtedness incurred before December 16, 2017. 

• IRS Publication 936