Thank you Bob & SJR for your thoughts, sorry for not including all the facts to help describe the transactions. Parents live in the home as their principal residence. Son is a joint owner in property but does not live there. Parents want to buyout son's share of house so they would own 100% of home going forward. No current mortgage on property but will pay son out over time with fair interest rate. Tryng to see if the interest paid to buy the other half qualifies as mortgage interest and can be a tax deduction.

Really appreciate your time and thoughts.

Steve