Also known as: plenae aetatis · full age · age of majority
Written by attorneys · grounded in primary & secondary sources — see below
The legal status of having attained the age at which a person possesses full capacity to enter into binding contracts, execute wills, and perform other legal acts without the protections or disabilities associated with minority. The age of majority is eighteen unless a statute provides otherwise. A person who has reached plena aetas may no longer disaffirm contracts or gifts on the ground of minority.
Parker Phillips, age seventeen, borrowed funds from a lender for speculative trading and later disaffirmed the obligation. After Parker turned eighteen, the lender sought enforcement. Because Parker had reached plena aetas, the court held the prior disaffirmance effective and refused to enforce the remaining balance.
Phoebe Park obtained a child-support order against her former spouse when their daughter was sixteen. The daughter reached plena aetas at eighteen while still attending college. The issuing state continued the order because the statute expressly extended support for a child who had attained the age of majority.
Select any source to read its text and confirm it supports the definition.
Pilar Pena and her partner began living together when Pilar was seventeen. After Pilar reached plena aetas, they signed a cohabitants' agreement allocating property rights. Because both parties had attained the age of majority, the agreement satisfied the statutory definition of cohabitant and was enforceable.
Pearl Porter's will created a trust for her children who held commercial licenses. Her genetic son Ulysses reached plena aetas before the testator's death and obtained the required license. The court included Ulysses in the class because the genetic parent had functioned as a parent before he attained majority.
Philip Powell turned eighteen and received notice of a trust accounting in a pending proceeding. Because Philip had reached plena aetas, the court treated him as a competent party entitled to direct notice rather than service through a guardian.
Pamela Phillips, age seventeen, signed an employment contract containing a wage schedule. Upon reaching plena aetas she continued working without objection. The court enforced the wage terms because Pamela had attained full age and ratified the agreement by performance.
A person reaches plena aetas at the age of majority, which is eighteen unless a statute provides otherwise. Contracts entered before that age are voidable at the minor's option. Once the person attains full age, the power to disaffirm generally ends.
Supporting sources
No. A former minor may still disaffirm a gift after reaching plena aetas, but failure to disaffirm within a reasonable time constitutes ratification. Courts measure reasonableness from the date of majority.
Yes. A child-support order may continue for a child who has attained the age of majority if the issuing state's law so provides. The definition of child-support order expressly includes such adult children.
An individual must have reached plena aetas or been emancipated before cohabitant status arises under the uniform act. Agreements concerning contributions are enforceable only when both parties satisfy that threshold.
…gender-based classifications. In Stanton v. Stanton , 421 U.S. 7 (1975), the Court held that a statute that imposed a greater age of majority on males than on females was unconstitutional. The Court held that the statute was not substantially related to the achievement of any important governmental objective. In Weinberger v.…