A health care agent is a person you choose to make medical decisions for you if a severe illness or injury makes it impossible for you to speak or decide for yourself. The document that grants this decision-making power to the person you select is called a medical power of attorney.

A health care agent may also be called a health care proxy or health care surrogate. The medical power of attorney may also be called a durable power of attorney for health care. The agent and the document may be called something else in your state.

Laws vary by state. But 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 you choose a health care agent, it's important to talk about and write down your medical care preferences. For example, you would talk about when to continue or stop life-support measures.