Who has testamentary capacity to make a will in California?

What the Law Says

California law sets clear, objective standards for who may make a valid will. The key requirement is 'testamentary capacity' — a legal determination about mental ability at the time the will is signed.

To have testamentary capacity in California, a person must meet two conditions: (1) be at least 18 years of age, and (2) be of 'sound mind' — meaning they understand the nature of the act of making a will, know the general nature and extent of their property, and recall the natural objects of their bounty (e.g., spouse, children, close relatives).

Importantly, having a medical diagnosis like dementia or Alzheimer’s does not automatically disqualify someone — courts look at functional ability at the exact time the will is executed, not general health status.

The law also allows people with certain mental disorders to make a will if they meet the functional test — even if they lack capacity to manage finances or enter contracts, they may still have sufficient understanding to make a valid will.

Statutory Text

An individual is not qualified to make a will if the individual: (1) Is under the age of 18 years; or (2) Does not have testamentary capacity at the time of execution of the will.

— Probate Code § 6100(a) — Who may make a will

Statutory Text

A person has testamentary capacity if the person is able to understand and appreciate the nature and consequences of the act of making a will, including the nature and extent of the person's property, the natural objects of the person's bounty, and the disposition the person is making.

— Probate Code § 6100.5(a) — Definition of testamentary capacity

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