Under New York law, an individual may appoint someone she trusts, for example, a family member or close friend, to decide about medical treatment if she loses the ability to decide for herself. She can do this by using a health care proxy in which a health care agent is appointed to make sure that health care providers follow her wishes. The agent can also decide how her wishes apply as her medical condition changes. Hospitals, nursing homes, doctors and other health care professionals must follow the agents' decisions as if they were the patients'. The individual can give her health care agent as little or as much authority as she wants. She can allow the agent to decide about all health care or only certain treatments.