Should I wait for my mortgage to mature?

No. Allow me to to begin shopping around for an interest rate at least 120 days before your mortgage matures. Lenders will often guarantee you an interest rate as much as 120 days before your mortgage matures. As long as you are not increasing your mortgage, they will cover the costs of transferring your mortgage as well. This means a rate promised well in advance of your maturity date, which eliminates any worries about higher rates and if rates drop before the actual maturity date, the lender will adjust your interest rate to the lowest it has been during the 120 days since the application was submitted.