This document contains final regulations amending the estate tax marital deduction regulations. The amendments are made to conform the estate tax regulations to recent court decisions in Estate of Clayton v. Commissioner, 976 F.2d 1486 (5th Cir. 1992), rev'g 97 T.C. 327 (1991); Estate of Robertson v. Commissioner, 15 F.3d 779 (8th Cir. 1994), rev'g 98 T.C. 678 (1992); Estate of Spencer v. Commissioner, 43 F.3d 226 (6th Cir. 1995), rev'g T.C. Memo. 1992-579; and Estate of Clack v. Commissioner, 106 T.C. 131 (1996). The amendments affect estates of decedents electing the marital deduction for qualified terminable interest property (QTIP) and the estates of the surviving spouses of such decedents.