A Practice Note explaining the California advance health care directive, which an individual can use to authorize an agent to act on the individual's behalf to make health care decisions for the individual and to provide health care instructions that express the individual's wishes regarding the individual's care, including end-of-life care. This Note provides information on the purpose and use of an advance health care directive in California, including drafting and execution requirements, rules applicable to agents designated in an advance health care directive, and information regarding the Advance Health Care Directive Registry.