The role of a healthcare proxy is to make medical decisions on your behalf when a doctor determines you can no longer make them yourself. The person you name, sometimes called your agent or surrogate, steps into your shoes with the medical team and speaks for your values, your prior instructions, and the choices you would make if you still could.1National Institute on Aging. Advance Care Planning: Advance Directives for Health Care
What Decisions the Proxy Makes
The central job is medical decision-making. That can mean consenting to a surgery, declining a treatment, choosing between care options your doctors present, or deciding whether to continue life-sustaining interventions like mechanical ventilation or artificial nutrition.2National Institute on Aging. Choosing a Health Care Proxy The proxy is not supposed to substitute their own preferences. They advocate for what you would want, based on conversations you have had and any written instructions you have left behind.
The role also extends into the daily work of being a patient when you cannot do it yourself. Your proxy can ask questions, request second opinions, and push back when a proposed course of care does not match what you have expressed. They can review your medical records and share relevant health information with providers who need it.2National Institute on Aging. Choosing a Health Care Proxy
This is where the work gets hard. A proxy may need to insist on a decision that other family members disagree with, or authorize the withdrawal of treatment they personally wish could continue. The loyalty runs to you and your stated wishes, not to the proxy’s own comfort or anyone else’s expectations.
When the Authority Turns On
A proxy has no authority over your medical care as long as you can make and communicate your own decisions. The power activates only when your attending physician determines that you lack the capacity to make healthcare decisions and documents that finding in your medical record.2National Institute on Aging. Choosing a Health Care Proxy
The physician’s determination typically has to be in writing and must address the cause, nature, and expected duration of your incapacity. In most states a single attending physician makes the call, though some states require two physicians to agree for certain decisions, particularly withdrawing life-sustaining treatment.
Activation is not a permanent switch. If you regain capacity after surgery or recover from a medical crisis, your authority over your own care returns and the proxy steps back. If you later lose capacity again, the proxy reactivates.
What a Healthcare Proxy Cannot Do
The role has real limits, and understanding them is as important as understanding the powers.
A proxy cannot override you while you still have decision-making capacity. The whole structure assumes you speak for yourself whenever you can; the proxy exists for the moments when you cannot.
The role does not cover your finances or legal affairs. A general durable power of attorney handles those matters and should not be confused with a healthcare proxy.1National Institute on Aging. Advance Care Planning: Advance Directives for Health Care
Access to your medical information is also narrower than people assume. Federal privacy law treats your healthcare proxy as your personal representative once the proxy’s authority is active, meaning hospitals and doctors must give the proxy the same access to records they would give you.3eCFR. eCFR 45 CFR 164.502 – Uses and Disclosures of Protected Health Information: General Rules But that access only begins once a doctor certifies you are incapacitated. Before that moment, HIPAA blocks your proxy from getting any information about your care. If you want someone to be able to talk with your doctors while you are still competent, that requires a separate HIPAA authorization form.
How the Role Differs from a Living Will
People often confuse these two documents, but they do different things. A living will is a set of written instructions specifying which treatments you do and do not want in particular medical scenarios, typically end-of-life situations like terminal illness or permanent unconsciousness.4Legal Information Institute. Living Will A healthcare proxy does not contain instructions. It names a person.
The limit of a living will is that it can only address situations you have anticipated. Medicine is messy, and the real-world scenario you face may not match the categories in your written instructions. A proxy can adapt. They weigh the specific circumstances, ask doctors questions in real time, and make judgment calls that a static document never could. The limit of a proxy without a living will is that they may be guessing about your preferences without written guidance to anchor them.5National Institute on Aging. Preparing a Living Will
That is why most planning experts recommend both. The living will gives your proxy a roadmap of your values and specific wishes. The proxy fills in the gaps and handles the situations your living will did not cover.
What Happens Without a Proxy
The role becomes easier to see by looking at its absence. Without a designated proxy, hospitals turn to default surrogate laws when you cannot make your own decisions. Most states establish a priority list, typically starting with your spouse or domestic partner, then adult children, parents, siblings, and sometimes a close friend. The doctor or hospital identifies whoever is highest on that list and available, and that person makes the calls.
The default system works adequately when your family agrees. It falls apart when they do not. Three adult children who disagree about continuing aggressive treatment can leave the hospital mediating a family conflict with no clear tiebreaker. Some states allow a majority decision; others have no mechanism for resolving the impasse, which can delay critical care decisions. People without nearby family may end up with a court-appointed guardian making choices for them, someone who has never met them.
A named proxy cuts through all of this. You decide in advance who speaks for you, and that designation overrides the default hierarchy.
When People Disagree with the Proxy
The role of a healthcare proxy is powerful but not absolute. Disputes between a proxy and the medical team, or between the proxy and other family members, happen more often than people expect, particularly around end-of-life care. A doctor may believe continued treatment is futile while the proxy insists on following your wish to pursue every option. Other relatives may disagree loudly with the proxy’s decisions and pressure the medical team.
Most hospitals have ethics committees that serve as mediators in these situations. The committee typically includes physicians, nurses, social workers, ethicists, and sometimes clergy or community members. They review the case, hear from all parties, and issue recommendations aimed at resolving the conflict in a way that respects the patient’s values. Ethics committee opinions are advisory, not binding, but they carry significant weight with both medical staff and families.
If the ethics process fails to produce agreement, the dispute may end up in court, where a judge can override the proxy or appoint a guardian. That outcome is slow, expensive, and stressful for everyone, which is one reason the strength of the role depends so heavily on something that happens before any crisis: thorough conversations with your proxy about what you want. The more clearly your proxy understands your wishes, the less room there is for anyone to challenge the decisions they make on your behalf.