Deductions & credits

Vanessa A:  I appreciate your info.  I; however, don't understand whether I have to use the entire 600K balance of the loan  for the limitation test or whether I can use the 40%( portion of my mortgage payments in 2023)  of the 600K outstanding balance.   Another way to ask this is to know whether I should use 240K or 600 K for line 2 part 2 of the deductible home mortgage interest worksheet.  Since this value on line 2 part 2 is obtained from "beginning of year balance on home debt originating after Oct 13, 1987 and before December 15, 2017, I would assume I would take 40% of all values in that section.    i don't get a good understanding of that from the Voss v. Commissioner case you sent.  Please help me.  Thanks.