Making medical decisions for someone else typically requires legal authority, either through a document the person signed in advance or through a default process established by state law. Whether you’ve been formally named as a healthcare proxy or you’re stepping into the role because a family member can no longer speak for themselves, the process involves understanding your legal standing, knowing what the person would want, and communicating effectively with their medical team.
How Legal Authority Works
There are two main documents that give someone the right to make healthcare decisions for another person. A durable power of attorney for health care names a specific person (called a healthcare proxy, agent, or surrogate) to make medical decisions when the patient can no longer communicate. A living will spells out the patient’s preferences for specific treatments, particularly emergency and end-of-life care. Both documents only take effect when the patient loses the ability to make their own decisions.
A third tool, known as a POLST or MOLST form (the name varies by state), works differently from advance directives. It’s an actual medical order signed by a clinician that addresses a patient’s current treatment needs. Unlike a living will, which kicks in under future conditions, a POLST form is immediately actionable. It travels with the patient across all care settings, from hospitals to nursing homes to the home, and it binds emergency medical workers. In some states, a POLST form can override other advance directives, including a healthcare power of attorney.
When No Documents Exist
If your loved one never signed advance directives, most states have laws that establish a default hierarchy of people authorized to make decisions. The typical order is: legal guardian, spouse, adult child, parent, sibling, grandparent, grandchild, then close friend. The doctor identifies the appropriate person based on this list. A few states, including Massachusetts, don’t have default surrogate laws, which means family members may have less formal authority and the process can require more negotiation with the medical team.
If no surrogate can be identified at all, hospitals may involve their ethics committee to evaluate the situation and recommend a decision-making approach.
What Counts as Losing Decision-Making Capacity
A patient has decision-making capacity if they can do four things: understand their medical situation, appreciate the consequences of each option, reason through the decision in a logical way, and communicate a choice. A doctor evaluates these abilities at the bedside. This is not the same as a legal finding of incompetence, which requires a court. A patient can lack capacity temporarily (during sedation or delirium, for example) and regain it later. Your authority as a surrogate only applies during the periods when the patient cannot meet those four criteria.
Two Standards for Making the Decision
Once you’re the decision-maker, the question becomes: how do you decide? There are two recognized standards, and which one applies depends on what you know about the person’s wishes.
The preferred approach is called substituted judgment. This means you make the choice the patient would have made if they could decide for themselves. It’s not about what you think is best. It’s about what they would want, based on conversations you’ve had, values they’ve expressed, and preferences they’ve shared over time. If they told you they’d never want to be on a ventilator with no chance of recovery, that guides your decision, even if it’s not what you would choose for yourself.
When there’s genuinely no information about what the patient would have wanted, the fallback is the best interest standard. This involves weighing the benefits and burdens of treatment based on what a reasonable person in the patient’s situation would want, considering factors like pain, quality of life, and overall prognosis. This is a harder position to be in, and it’s the main reason having advance care conversations matters so much before a crisis hits.
Your Rights as a Surrogate
If you hold a healthcare power of attorney, federal privacy law (HIPAA) treats you as the patient’s “personal representative.” That means healthcare providers must let you inspect and receive copies of the patient’s medical records, just as the patient could. You need this access to make informed decisions, so don’t hesitate to request records, test results, and care summaries. Bring your legal documents to the hospital or clinic so they can be placed in the patient’s file.
Talking to the Medical Team
The most important part of this role is communicating clearly with doctors and nurses. You’re the bridge between what the patient values and what medicine can offer. A few practical approaches make this easier.
Start by telling the care team you’re the patient’s surrogate and that you’d like to discuss their wishes. Ask the team to explain the diagnosis, prognosis, and available treatment options in plain language. If something isn’t clear, say so directly: “I don’t understand what you just said” is a completely appropriate thing to tell a doctor. Ask when the doctor has time for a longer conversation if the moment isn’t right.
The most useful questions to ask center on what each treatment will actually accomplish. Will it cure the condition, manage symptoms, or just buy time? What are the side effects? What does recovery look like? If the patient’s condition is unlikely to improve, ask what shifting from aggressive treatment to comfort-focused care would look like in practice. These conversations help you match medical options to what the patient would want.
Decisions About Life-Sustaining Treatment
Some of the hardest decisions involve mechanical ventilation, feeding tubes, and resuscitation. Most jurisdictions protect a patient’s right to refuse medical treatment, and a surrogate can exercise that right on the patient’s behalf. Decisions to withhold or withdraw life-sustaining treatment should be made collaboratively with the medical team, considering the patient’s values, preferences, and overall prognosis. Some states have specific documentation requirements or, in rare cases, require court involvement for certain types of treatment withdrawal.
If you’re unsure whether the patient would want a particular intervention, say that honestly. The medical team can walk you through the likely outcomes of each path, which often makes the decision clearer. You’re not expected to have medical expertise. You’re expected to know the person.
When There’s Disagreement
Conflicts sometimes arise between family members, or between the surrogate and the medical team. If family members disagree about the right course of action, the legally designated proxy has the final say, assuming one has been named. When no proxy exists and family members disagree, or when the medical team has concerns about a surrogate’s decisions, either side can request a hospital ethics consultation.
Ethics committees serve an advisory role. They evaluate the situation, help identify the appropriate decision-making standard, and recommend a course of action. In most cases, their involvement helps clarify who should be making the decision and what standard should guide it, often resolving the conflict without the need for legal proceedings. In rare situations where disagreements can’t be resolved, a court may need to appoint a guardian.
Preparing Before a Crisis
If you’ve been asked to serve as someone’s healthcare proxy, the most valuable thing you can do is have detailed conversations now. Ask what kinds of treatment they would or wouldn’t want. Ask under what circumstances they’d want to shift from fighting an illness to focusing on comfort and quality of life. Write down what they tell you. These conversations don’t need to happen all at once; in fact, revisiting them over time as health changes is more useful than a single sit-down.
Make sure copies of all legal documents are easy to find. The person’s primary care doctor should have a copy in their medical record. The proxy should keep a copy accessible at home and, ideally, in a digital format on their phone. If the person is admitted to a hospital, bring the documents early so staff can add them to the chart. Some states maintain electronic registries for advance directives, which is worth checking.
Being someone’s medical decision-maker is one of the most significant responsibilities another person can give you. The weight of it is real, and the guilt or second-guessing that comes afterward is common and normal. The best protection against that, for both of you, is knowing as clearly as possible what they would choose for themselves.