The fertile-octogenarian rule is a mostly outdated concept, for the purposes of the rule against perpetuities, that a person is capable of having children no matter the age. The rule against perpetuities requires the owners of property in a will to be ascertainable within a certain period of time. The fertile-octogenarian rule means that if a person having a child would break the rule against perpetuities, the person will be considered capable of having a child no matter their age or physical condition. Most states have changed this rule by limiting the age of fertility considered for the rule, or instead of considering what could possibly occur, some states wait and see what actually occurs to see if the rule is broken.
[Last updated in July of 2021 by the Wex Definitions Team]