N.Y. GOB Law § 5-705

§ 5-705. Execution and acknowledgment of assumption of mortgage debt\nby grantee of mortgaged real property. No grantee of real property shall\nbe liable upon any indebtedness secured by a mortgage thereon executed\nprior to the time of the conveyance of the real property to the grantee,\nnor shall he be liable for any deficiency that may remain upon the\nforeclosure and sale of real property covered by such a mortgage, after\napplication of the proceeds of sale, unless such grantee shall\nsimultaneously with the conveyance to him of such real property execute\nand acknowledge, before an officer authorized to take acknowledgments of\ndeeds, a statement in writing stating in substance that such grantee\nassumes and agrees to pay such mortgage debt and giving the specific\namount of the debt assumed. The execution and acknowledgment by a\ngrantee of the deed of conveyance to him containing such written\nstatement shall be sufficient compliance with the provisions of this\nsection. This section shall not apply, however, where, subsequent to the\nconveyance and upon an extension or modification of the indebtedness\nsecured by the mortgage, the grantee shall execute and acknowledge,\nbefore an officer authorized to take acknowledgments of deeds, a\nstatement in writing stating that such grantee assumes and agrees to pay\nsuch mortgage debt, and giving the specific amount of the debt assumed.\n