The Third Department explained the “unjust enrichment” issues raised when a party holds two mortgages on the same property, forecloses on the junior mortgage, purchases the property at the foreclosure sale, and then sues on the senior mortgage:
Where, as here, a holder of two mortgages forecloses on the junior mortgage and purchases the property, the question of whether the senior obligation is recoverable is a matter of equity dependent upon the facts and circumstances of the case (see Restatement [Third] of Property § 8.5, Comment c [2]…). When the sale price and the outstanding amount owed on the senior obligation together equal the fair market value of the property, the land is considered to satisfy the debt. In that case, equity will prevent the mortgagee from suing on the senior obligation and thus receiving a windfall (see Restatement [Third] of Property § 8.5, Comment c [2]…).
If, however, the fair market value of the property is less than the sum of the two obligations, “the mortgagor would be unjustly enriched if the mortgagee is prevented from recovering on the senior obligation” (Restatement [Third] of Property § 8.5, Comment c [2]). In such a situation “the mortgagee may recover on the senior obligation only the amount by which the sum of the junior and senior obligations exceed the fair market value of the land” (Restatement [Third] of Property § 8.5, Comment c [2]). Here, neither party submitted proof as to the fair market value of the property, and Supreme Court thus had no basis to determine the amount recoverable on the senior note. We remit for that purpose. TD Bank NA… v Dunbar Tower LLC, 516770, 3rd Dept 12-12-13