Extra Payments toward Primary Residence Mortgage?

[Jess Friedman]

Hi all! I own two long-term rental properties (1 duplex and 1 single family) and also own a primary residence that I live in. The duplex will be fully paid off in two years (3% interest rate) and the single family is only about five years in (3.625% interest rate). That was my primary residence for five years before I converted it to a rental property. My primary residence was purchased in October 2025 (6.375 interest rate).
My question is, should I make an extra monthly payment towards the principle on the primary residence's mortgage to save on interest? I am not sure if I will be in the house longer than 5 years and am not sure what to do and what is beneficial. Thank you all for your knowledge and advice in advance! 

[Jess Friedman]

@Jules Aton Yep, I've had the duplex since 2015. Can't wait to be done with the loan! I don't plan on contributing any extra monthly payments to either rental property as both have all expenses covered by tenants' rents.