Where do you enter a federal and state difference in the amount of mortgage interest deduction? CA didn't conform to the new fed limits so the CA deduction may be higher

CA has a long history of not conforming to the IRC.  For the most part, deductions that are allowed on both federal and CA, albeit to different extent, generally do not require separate entries and differences would be accounted for on Sch CA(540).

Specific entries for CA, nevertheless, may be required for deductions that are allowed for only CA but not for federal - haven't looked at the setup in Lacerte this year but deductions such as qualified moving expenses (for civilians), foreign real estate taxes, and misc I/D could be among those.

Unfortunately, I believe all the interest info must not be input down at the bottom of Screen 25 for Excess Mortgage. If done correctly it will limit federal and carry what should go to CA Schedule CA correctly. I have not yet spent the time necessary to verify the program accuracy. My first dummy try did NOT work correctly, but it might have been my input. 

https://accountants-community.intuit.com/articles/1606103-entering-home-mortgage-interest-and-other-...