An advance medical directive is a legal document that spells out your wishes for medical care if you become too ill or injured to speak for yourself. It only takes effect when you can’t communicate your own decisions. Roughly one in three U.S. adults has completed some form of advance directive, which means the majority of people have no formal plan in place for this situation.
There are two main types: a living will and a durable power of attorney for health care. They serve different purposes, and most people benefit from having both.
What a Living Will Covers
A living will is a written document that details which medical treatments you would or would not want used to keep you alive. It applies specifically to situations where you can no longer make decisions yourself, typically during end-of-life care or after a severe medical event.
The treatments you can address in a living will include:
- CPR: Whether you want your heart restarted if it stops beating, either through chest compressions or an electric shock.
- Mechanical ventilation: Whether you want to be placed on a breathing machine, and if so, for how long.
- Pacemakers and implantable defibrillators: If you already have one of these devices, when you would want it turned off.
- Artificial nutrition and hydration: Whether you want to receive food and fluids through a tube if you can no longer eat or drink.
- Dialysis: Whether you want kidney filtration continued if your kidneys fail.
One important nuance: a “do not resuscitate” order and a “do not intubate” order are not the same thing, even though they’re often treated as a package deal. A DNR addresses what happens when your heart stops. A DNI addresses whether a breathing tube should be placed, which can come up in situations well before cardiac arrest, like severe pneumonia. Research published in the Journal of Hospital Medicine found that 28% of hospitalized patients who had agreed to both a DNR and DNI would actually have accepted a trial of mechanical ventilation for pneumonia. That gap highlights why it’s worth thinking through each scenario separately rather than checking a single box.
Durable Power of Attorney for Health Care
The second component is naming a health care proxy, sometimes called an agent, surrogate, or representative. This is a person you authorize to make medical decisions on your behalf when you cannot. Unlike a living will, which covers specific treatments you’ve already thought through, a proxy can respond to situations you didn’t anticipate.
You control how much authority your proxy has. You can grant them broad decision-making power across all medical choices, or limit them to a few specific ones. You can also require that they consult certain family members before making a decision, or designate some choices to be made by your doctor instead.
A proxy’s responsibilities can be extensive. They may decide which treatments, procedures, or services you receive, choose your health care providers and where you receive care, access your medical records, and even make decisions about organ donation and what happens to your body after death. These powers only activate when you are too sick to make decisions yourself.
Who Should Not Be Your Proxy
The American Bar Association recommends against choosing your doctor, anyone employed by your health care provider, the owner or operator of your care facility, or anyone working for a government agency that’s financially responsible for your care. A court-appointed guardian or conservator is also generally not appropriate, nor is someone who already serves as proxy for ten or more other people. The goal is to pick someone who knows your values, can advocate firmly on your behalf, and has no professional conflict of interest.
When an Advance Directive Takes Effect
Your advance directive sits dormant until a medical professional determines you lack decision-making capacity. This isn’t a single dramatic moment. Doctors informally assess capacity at every encounter. You have capacity if you can understand your medical situation, appreciate the consequences of your choices, reason through the options, and communicate a decision.
A more formal evaluation gets triggered by specific red flags: a sudden change in mental status, refusing a treatment that’s clearly beneficial without explanation, or agreeing to a risky procedure without seeming to weigh the risks. If that evaluation finds you lack capacity, your advance directive activates and your proxy steps in.
Making It Legally Valid
Requirements vary by state, but at a minimum your advance directive must be in writing and signed by you. Most states require either notarization, two witnesses, or both. Witnesses typically cannot be your health care provider, anyone named as your proxy, or an operator of a care facility where you live. Some states accept notarization in place of witnesses, while others require all three. Check your state’s specific rules, as a directive that’s valid in one state may not automatically be recognized in another.
Many hospitals and state bar associations provide free, state-specific forms. You do not need a lawyer to complete one, though legal advice can help if your situation is complex.
Storing and Sharing Your Directive
An advance directive is useless if no one can find it during an emergency. Give copies to your health care proxy, your primary care doctor, and any specialists who manage ongoing conditions. Ask that it be added to your medical record. Keep the original in a place your family knows about and can access quickly, not a safe deposit box that requires a key or court order. If you’re admitted to a hospital, bring a copy or confirm one is already in your file.
Some states maintain electronic registries where you can upload your directive so emergency responders and hospital staff can access it. Your state health department’s website is the best place to check whether this option exists where you live.
Updating or Revoking Your Directive
You can revoke all or part of your advance directive at any time, and you can replace it with a new one whenever your wishes change. If you do revoke it, destroy all old copies to prevent confusion. Major life events are natural triggers to revisit the document: a new diagnosis, a marriage or divorce, the death of your named proxy, or simply a change in how you feel about certain treatments. There’s no limit on how many times you can update it.
Because your proxy’s authority only activates when you lack capacity, updating the document while you’re healthy and clearheaded is straightforward. The new version simply supersedes the old one, as long as it meets your state’s signing and witnessing requirements.