Paying off or keeping rental mortgages in retirement.

[Bob Oliver]

Trying to decide on using reserves to pay off rental mortgage or keep. I am retired, 72 and own 4 college rental houses. Zero vacancy as housing shortage is acute and typically let students pick their successors. I still handle minor repair calls but contract larger jobs as my stiffness increasingly manifests itself and I need the deductions. Considering payoff of smallest note of $35,500 @ 3.25% and 4 yrs remaining (multiple refi over the years). Currently rental income on this 4BR/1BA is $1940 and will incr to $2200 6/1/24. Not buying any more properties at this stage of life as burning gas in the RV far more appealing than more debt, not to mention the price of rentals in my area. Cash flow is key focus as these rentals are my retirement income. Can someone point me to a calculator or thought processes for weighing the benefits of payoff-not payoff?