A health care agent is a person chosen to make medical decisions for another, should a severe illness or injury occur that makes communication impossible. The document that grants this decision-making power to the person selected is called a medical power of attorney.

A health care agent may also be called a health care proxy or surrogate or an attorney-in-fact.

Although laws vary by state, a health care agent can usually make medical treatment decisions at the end of life or anytime a person is not able to communicate. As soon as a person selects a health care agent, it is important to thoroughly discuss and document medical care preferences, such as when to continue or abandon life-support measures.