As clarified before, this question is *not* about a refinance, but how to apply the mortgage interest deduction limits to a primary home + second home.
Pub 936 defines 3 categories:1) before 19872) before Dec 16, 2017 and under 1M3) after Dec 16 2017 and under 750kPub 936 says if all mortgages fall in one or mo...