The short answer
A health care proxy is the person you name to make medical decisions if you cannot make them yourself. NCI describes this as one of two main advance directives, the other being a living will. NCI advises completing these while you are well, reviewing them with your care team, sharing copies, and changing them whenever your wishes change.
NCI describes advance directives as documents that tell loved ones and doctors what care you want if you cannot say so yourself.
A health care proxy, also called an agent or surrogate, is the person you appoint to decide for you.
A living will is the separate document that records which treatments you would want.
NCI advises completing these while you are healthy rather than during serious illness.
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What the document is for
An advance directive tells your loved ones and doctors what kind of medical care you want. It speaks for you when you cannot tell them yourself. That is NCI's description. It is a legal document, and it exists for one narrow but important moment. You cannot speak for yourself. A decision still has to be made.
NCI describes two main types.
A living will sets out whether you want life-sustaining treatments. These include ventilators, CPR or tube feeding.
A health care proxy names a trusted person to make medical decisions for you. It is created through a durable power of attorney for health care. NCI notes this person may be called a health care agent, a surrogate or a proxy. The name depends on where you are.
Why naming a person matters as much as writing a list
A living will states whether you want certain kinds of care. A health care proxy is a person who can make decisions about your medical care if you cannot. The two serve different purposes, and many people complete both.
What to look for in the person
NCI does not say who to appoint. But the shape of the role suggests what it asks for. The person needs to know your wishes well. They need to represent them faithfully. And they need to state them clearly in a hospital corridor at a hard hour.
Two things get mixed up here. One is who is closest to you. The other is who stays steady under pressure. Sometimes that is the same person. Sometimes it is not. Naming a sibling rather than a spouse is not an insult. It can be a kindness.
Talk to the person before naming them. Being appointed by surprise, in a crisis, is a hard thing to do to someone.
Do it early
NCI's advice on timing is clear. Ideally you complete these documents while you are healthy. Do not wait for serious illness. Calm decisions are better decisions. They are also easier for everyone to trust later.
Getting help with the forms
You do not have to work this out alone. NCI suggests discussing your choices with your doctor, nurse or social worker. It also notes that most health care facilities help people complete the documents.
Ask your care team who can help with the forms where you are being treated.
Tell people, then tell them again
NCI describes the steps after signing:
- Review the documents with your health care provider to make sure they are accurate.
- Give copies to your doctor, your hospital and your family.
- Store them safely, where they are easy to get to.
- Consider carrying a wallet card that says the documents exist.
Have the conversation, not just the paperwork
NCI lists benefits to talking with loved ones about your wishes. It helps make sure your wishes are known. It can comfort your family and ease their burden. And it can give you peace of mind and help you worry less about the future.
Nothing here is permanent
NCI is clear on this point. You can change your mind at any time. If you do, talk with your doctor and your loved ones about the new decision, and make sure the version on file at your hospital is the current one.
Common questions
Is a health care proxy the same as a living will?
No. NCI describes them as the two main types of advance directive. A living will records the treatments you would or would not want. A health care proxy names another person to make decisions about your medical care if you cannot make them yourself.
Who should I choose?
This is a personal decision, and NCI's advice is to discuss your choices with your doctor, nurse or social worker. Talk it over with that person and with your loved ones.
What happens after we sign?
NCI advises reviewing the documents with your health care provider, giving copies to your doctor, hospital and family, and storing them safely where they are easy to get to.
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Sources last checked: 2026-08-11 what this meansLast updated: 2026-10-16Next planned review: 2027-08-11
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Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and then compared with the sources listed on it, looking for statements those sources do not back up. That check is not a sentence-by-sentence record and can miss errors. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
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