the $1 million debt limitation continues to apply to any indebtedness incurred on or before 12/15/2017 including refinanced qualified residence indebtedness originally incurred before that date to the extent the amount and term of the refinancing does not exceed the amount and term of the original indebtedness. IRC Code Sec 163(h)(3)(F)

Thank you very much!  That's how I understand the situation also.  Do you know how to accurately input/report 1098s to reflect this and trigger the $1mm limit?  As entered now following the default interview prompts, the TT software determined our qualified loan limit to be $750k (line 11 on Deductible Home Mortgage Interest Worksheet).  To compound the problem, the software summed our three 1098s issued in 2020 (initial, refinance,  refinance under new service company) to determine the average balance of debt (line 7, same Worksheet).  The software then uses this  3x value as denominator in line 15 to effectively reduce the deductible interest by two thirds!

Thank you in advance for any advice!