N.Y. Real Property Actions & Proceedings Law § 1301

§ 1301. Separate action for mortgage debt. 1. Where final judgment for\nthe plaintiff has been rendered in an action to recover any part of the\nmortgage debt, an action shall not be commenced or maintained to\nforeclose the mortgage, unless an execution against the property of the\ndefendant has been issued upon the judgment to the sheriff of the county\nwhere he resides, if he resides within the state, or if he resides\nwithout the state, to the sheriff of the county where the judgment-roll\nis filed; and has been returned wholly or partly unsatisfied.\n 2. The complaint shall state whether any other action has been brought\nto recover any part of the mortgage debt, and, if so, whether any part\nhas been collected.\n 3. While the action is pending or after final judgment for the\nplaintiff therein, no other action shall be commenced or maintained to\nrecover any part of the mortgage debt, including an action to foreclose\nthe mortgage, without leave of the court in which the former action was\nbrought. The procurement of such leave shall be a condition precedent to\nthe commencement of such other action and the failure to procure such\nleave shall be a defense to such other action. For purposes of this\nsubdivision, in the event such other action is commenced without leave\nof the court, the former action shall be deemed discontinued upon the\ncommencement of the other action, unless prior to the entry of a final\njudgment in such other action, a defendant raises the failure to comply\nwith this condition precedent therein, or seeks dismissal thereof based\nupon a ground set forth in paragraph four of subdivision (a) of rule\nthirty-two hundred eleven of the civil practice law and rules. This\nsubdivision shall not be treated as a stay or statutory prohibition for\npurposes of calculating the time within which an action shall be\ncommenced and the claim interposed pursuant to sections two hundred four\nand two hundred thirteen of the civil practice law and rules.\n 4. If an action to foreclose a mortgage or recover any part of the\nmortgage debt is adjudicated to be barred by the applicable statute of\nlimitations, any other action seeking to foreclose the mortgage or\nrecover any part of the same mortgage debt shall also be barred by the\nstatute of limitations.\n