in your situation when you file married separate the limitation on your mortgage interest deduction is
375,000 divided by your average mortgage balance for 2023 times the mortgage interest
see IRS PUB 936. this is the maximum you can deduct.
other factors that could affect the amount you can deduct include
1) do you live in a community property state
2) who names are on the mortgage
3) who paid the mortgage and was it paid from a joint or separate account
thus in some cases your limit may be just 1/2 of the interest. the worksheets the iRS provides can not be used.
