I entered two 1098s, one for primary home (acquired before Dec 2017), one for second home (bought after Dec 2017).
TurboTax seems to apply the deduction limits (1M & 750k) to each 1098 individually and concludes all interest (on a total balance > 1M) is deductible.
My understanding is one should apply a limit to the total balance outstanding on both homes. But somehow, because each property falls on difference sides of the Dec 2017 rules change, TurboTax seems to apply the limits separately, allowing me to deduct interest up to 1M+750k=1.75M. (if I change the dates on either mortgage the behavior in TurboTax changes and either the 1M or 750k limit is applied).
How to enter this correctly in TurboTax?
(I.e. using Table 1 of Part II of Pub 936)
