Is the cost of mortgage reinstatement full or partly tax deductible on an investment property?

[Anonymous_]

It depends upon what the proceeds were used for (i.e., only interest paid on the loan balance that is used to buy, build, or improve the investment property is potentially deductible as investment interest) and the amount of your investment income from interest and ordinary dividends minus any qualified dividends. You may have to complete Form 4952 to determine the latter.

See https://www.irs.gov/instructions/i1040sca#idm140545383096000  

and

https://www.irs.gov/pub/irs-pdf/f4952.pdf

[letsmakeadealtoday]

A mortgage reinstatement is where person X cannot pay any mortgage payments so their mortgage goes into foreclosure.  Person Y comes along and either a) pays the entire outstanding loan balance of hypothetically $153,246 or b) does a mortgage reinstatement in which only the accrued mortgage payments which have not been made, (from when person X stopped paying until today) of hypothetically $37,296 are made and person Y agrees to pay future mortgage payments as they come due.

In this example, the future payments are roughly $153K minus $37K or $116K.   My question was, if Person Y pays the accrued $37K  (the payments needed to bring the mortgage current) is any portion of that tax deductible?  Thank you!