Here is the TurboTax link that explains how to handle multiple 1098 forms. You are correct, the interest is a key factor when you have multiple mortgages.
Unfortunately when you refinance your mortgage and combine a home equity loan, for example, the mortgage interest from the new loan isn’t tax deductible. Only the loan amount when you originally acquired the property remains deductible.
https://www.irs.gov/publications/p936 No matter when the indebtedness was incurred, you can no longer deduct the interest from a loan secured by your home to the extent the loan proceeds weren't used to buy, build, or substantially improve your home.
It is important to follow the steps carefully so that the interest is handled correctly.
@mwahl0
