It’s not unusual for older estate plans to include a “formula
funding clause,” which splits assets between a credit shelter trust and the
surviving spouse (either outright or in a marital trust). A formula clause
works well when an estate is substantially larger than the exemption amount.
However, now that the estate tax exemption is set at an inflation-adjusted
$10 million ($11.4 million for 2019), that may no longer be the case
for many families. Thus, a formula funding clause can lead to undesirable
results, including inadvertent disinheritance of one’s spouse.