Jackson v. United States 376 U.S. 503, 84 S.Ct. 869 (1964) Richards died. The California Probate Court allowed his widow, Jackson, to take $3k a month out of the estate for two years for support and maintenance. That's called a widow's allowance. It took the Probate Court 14 months to make this determination, so they gave her $42k in back pay, and then $3k a month for the next 10 months. That's $72k total. When Richards' Federal estate tax return was filed, the $72k was claimed as a marital deduction. The IRS denied the deduction and demanded payment of taxes. Jackson appealed. The Federal District Court granted summary judgment to the IRS. Jackson appealed. In general, $$$ going to a decedent's surviving spouse is non-taxable. However, assets that are considered terminable do not qualify for the deduction. Terminable interests are those that could (either due to time or some contingency) pass to someone other than the surviving spouse. The Federal District Court found that an allowance to a widow was a terminable interest and not deductible under the marital provision of the IRS Code. The Federal Appellate Court affirmed. The US Supreme Court affirmed. The US Supreme Court found that under California State law, the widow's allowance ends if the widow gets remarried or dies. Therefore, the payments could have been terminated upon a contingency. Therefore it is a terminable interest under IRS regulations.