Ind. Code § 34-11-6-2

Sec. 2. A contract, sale, release, or conveyance executed by a person after reaching the person's eighteenth birthday may not be avoided by the person on the grounds that, at the time the agreement was executed, the person was acting under a legal disability by reason of the person's age. A person who executes an agreement after reaching the person's eighteenth birthday may not assert legal disability by reason of age as a defense in an action to enforce a contract against the person.