26 CFR §20.2056(b)-3 — (b)-3 Marital deduction; interest of spouse conditioned on survival for limited period.

1. (a)In general. Generally, no marital deduction is allowable if the interest passing to the surviving spouse is a terminable interest as defined in paragraph (b) of § 20.2056(b)(1). However, section 2056(b)(3) provides an exception to this rule so as to allow a deduction if (1) the only condition under which it will terminate is the death of the surviving spouse within 6 months after the decedent's death, or her death as a result of a common disaster which also resulted in the decedent's death, and (2) the condition does not in fact occur.
2. (b)Six months' survival. If the only condition which will cause the interest taken by the surviving spouse to terminate is the death of the surviving spouse and the condition is of such nature that it can occur only within 6 months following the decedent's death, the exception provided by section 2056(b)(3) will apply, provided the condition does not in fact occur. However, if the condition (unless it relates to death as a result of a common disaster) is one which may occur either within the 6-month period or thereafter, the exception provided by section 2056(b)(3) will not apply.
3. (c)Common disaster. If a property interest passed from the decedent to his surviving spouse subject to the condition that she does not die as a result of a common disaster which also resulted in the decedent's death, the exception provided by section 2056(b)(3) will not be applied in the final audit of the return if there is still a possibility that the surviving spouse may be deprived of the property interest by operation of the common disaster provision as given effect by the local law.
4. (d)Examples. The application of this section may be illustrated by the following examples: