The growing elderly population and the acquired immunodeficiency syndrome (AIDS) epidemic have focused attention on ethical and legal issues surrounding health-care decision making. It is becoming increasingly critical to involve patients in the decisions that affect their care. Legal frameworks are evolving to protect the rights of both "competent" and "incompetent" patients. By writing instructions in advance, patients can increase their control and autonomy over health-care decisions. Physician assistants can facilitate the process by incorporating a patient value history into the chart and explaining legally recognized documents. Living wills generally apply in the context of terminal illness or irreversible coma; however, definitions of terminal conditions, imminent death, or life-sustaining procedures can be problematic. A number of states recognize the health-care durable power of attorney, which establishes a surrogate decision maker to act with specific instructions and limitations should the patient become incompetent or incapacitated.