ORDERED that the order is affirmed, with costs.
A separation agreement, which, as here, does not merge into the judgment of divorce, survives as a separate contract to which the parties are bound (see, Riley v. Riley, 179 A.D.2d 750 ; Lambert v. Lambert, 142 A.D.2d 557 ). Consequently, while a judgment of divorce may be attacked pursuant to CPLR 5105, the underlying separation agreement will remain unimpeached unless challenged in a plenary action (see, Riley v. Riley, supra; Culp v. Culp, 117 A.D.2d 700 ). The failure of the defendant to commence a plenary action is fatal to his application.
S. MILLER, J.P., THOMPSON, KRAUSMAN, FLORIO, and SCHMIDT, JJ., concur.