An action to foreclose a mortgage is subject to a six-year statute of limitations. Where the mortgage is payable in installments, a separate cause of action accrues for each unpaid installment, and the limitations period begins on the due-date of each installment. If a mortgage debt is accelerated, the entire amount is due and the limitations period begins on the entire debt. A lender may revoke its election to accelerate the mortgage, but it must do so by an affirmative act during the six-year limitations period subsequent to the commencement of the prior foreclosure action.
Wilmington Trust, N.A. v. Dawson, NY Slip Op 05583 (2d Dep't July 10, 2019)
Here is the decision.