Can a mentally delayed person make a power of attorney?

Under Oklahoma law, a person with mental delay or diminished capacity may be able to execute a power of attorney (POA), but only if they possess sufficient mental capacity to understand the nature and effect of the document at the time of execution. A POA is a legally binding authorization that allows one person (the principal) to grant another (the agent) authority to act on their behalf. Under 58 O.S. § 3009, a POA can take effect immediately or upon a determination of incapacity. However, to create a valid POA, the principal must have the legal capacity to contract and to understand the powers being granted when signing the document.[1]

Legal Capacity Standard

Oklahoma courts and statutes generally apply a contractual capacity standard: the principal must comprehend the nature and consequences of granting authority to another. If a person is under guardianship or has been adjudicated incapacitated by a court, they likely lack the capacity to execute a POA unless the court restores capacity or authorizes it through a limited guardianship under 43A O.S. § 1-103 (as described in HB 1566). Mentally delayed individuals are not automatically deemed incapacitated; their capacity must be evaluated case by case.[2]

Attorney and Ethical Guidance

Under Oklahoma Rules of Professional Conduct, Rule 1.14, when a lawyer represents a client with diminished capacity, the lawyer must maintain a normal relationship as much as possible and take protective action only when the client cannot adequately act in their own interest. This implies that if a mentally delayed person can understand the purpose of a POA, an attorney may ethically assist in preparing it.[3]

Practical Application

If uncertainty exists concerning the person's capacity, it is advisable to obtain a physician's or psychologist's written evaluation to document capacity. A durable POA may also become effective upon later incapacity, ensuring continued authority if the principal later becomes unable to make decisions.

Conclusion: A mentally delayed individual can execute a power of attorney in Oklahoma if they understand the nature and effect of the act at the time. If their understanding is limited or questionable, legal or medical evaluation should support the validity of the document, or a guardianship proceeding may instead be appropriate.