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Medical power of attorney


Medical power of attorney is a legal document where one person gives another person the power to make medical decisions for them once they can no longer do so for themselves. This article defines medical power of attorney and explains when its powers start and end. It also lists some of the key powers a person with medical power of attorney does and does not have. Finally, it discusses some of the factors to consider when deciding which person to give that responsibility to.

What is medical power of attorney (MPOA)?

Medical power of attorney is a legal document where one person, called the principal, gives another person, called the medical proxy or medical agent, the power to make medical decisions for them. The proxy is usually a family member, spouse, or close friend. Medical power of attorney is also called health care power of attorney or health care proxy.

When do the proxy’s powers start?

A medical power of attorney document becomes legally valid as soon as it is signed. However, the proxy does not receive their power to act until the principal is unable to make decisions for themselves. 

In other words, as long as the principal is mentally competent, is physically capable, and can make themselves understood, their own decisions about their treatment and care are the ones that medical and health care providers will follow. The proxy cannot overrule the principal’s decisions.

When do the proxy’s powers end?

Once a proxy has received the power to make medical decisions, this power generally only ends under four conditions:

  1. If the principal legally revokes (takes back) the power of attorney 
  2. When the principal dies
  3. If the proxy decides to give up their medical power of attorney 
  4. When the proxy is a spouse whom the principal divorces after giving them medical power of attorney (in some states)

The fact that the person with medical power of attorney can make decisions when the person is no longer capable means that an MPOA is automatically durable—that is, permanent.

What can the proxy do?

Once they receive the power to act, the proxy is able to make many major health care decisions for the other person. Some examples are:

  • Where the person is going to live (at home, in long-term care, in assisted living, etc.)
  • Who the person’s doctors will be
  • What the person eats and who will bathe them
  • Whether the person receives hospital care or home care
  • Whether the person is given surgery, medical treatments, psychiatric treatment, etc. 

In all these decisions, the proxy is legally required to act in the best interests of the person.

What can’t the proxy do?

A medical proxy or agent has very broad powers to make decisions for their loved one. However, decisions that the loved one made while they were still competent, and which they put into legal documents, will overrule a medical proxy’s decisions.  These include:

  • A will. The medical proxy does not have the power to alter any aspect of the principal’s will. They also cannot make decisions about the principal after their death, unless they are also the executor of the will. (In that case, the power to act comes from the will, not the MPOA document.)
  • A living will. Doctors and other health care providers can and must follow the instructions in a living will, such as the person’s decision not to receive chemotherapy or experimental drugs, rather than the ones given to them by a medical proxy.
  • Do Not Resuscitate or Do Not Intubate orders. These advance directives, which the person made when they were mentally and physically competent, override any other legal document, including medical power of attorney.

A medical proxy also cannot give their medical power of attorney to someone else. If they decide to give up their power, it will go to the next person on the list, if the principal has named alternatives. If the principal has not done this, the state will usually appoint a person to act on their behalf. This may or may not be someone whom the principal would want making medical decisions for them.

Who should be a medical proxy?

Choosing a medical proxy is an extremely important decision. The person deciding should make sure that their proxy has certain qualifications:

  • They should be able and willing to act as a proxy. This usually includes living close enough to the principal that they can be on hand to assess situations and make on-the-ground decisions. However, about 10% of medical proxies live more than an hour away from their loved one.1 This is legal; it just makes things more challenging.
  • They should be someone who knows the principal well, and who understands and respects their values, beliefs, and decisions. 
  • They should be someone who fully understands the duties involved, including the emotional strain that acting as proxy can create.
  • They should be someone who can work well with other caregivers, such as family members and friends, during a difficult time. If the person with financial power of attorney is separate from the medical proxy, the proxy should be someone willing to communicate and coordinate with the person holding financial power of attorney.

Can medical power of attorney be revoked?

The person who created the medical power of attorney can easily take it back or switch it to another person at any point up until the time that they are incapacitated—that is, unable to make or communicate decisions for themselves. 

They can do this by signing a form revoking the MPOA and, in most states, getting it signed by a notary. If they are switching the power of attorney to someone else, they and a notary (where applicable) can sign a new MPOA form that says they revoke the previous version.

However, once medical power of attorney takes effect, it is very difficult to take back or change. This is because, as mentioned, it only takes effect once the principal is no longer able to make decisions for themselves. For instance, a stroke may have made them unable to speak, or their dementia may have made them unable to understand the consequences of what they’re saying. 

Since the principal can no longer make or communicate decisions for themselves, they cannot at that point decide (or communicate the decision) to take back a proxy’s power of attorney, or to change it to someone else. Even if they are being abused or neglected, neither they nor their family members will likely be allowed to take away the proxy’s power of attorney. 

It is therefore very important that the principal chooses their proxy carefully and communicates fully with that person and all their loved ones and health care providers. It is also important for the principal to name alternatives to their first choice, in case the first proxy decides to give up the position or is unavailable for some reason.

Related information

Advance directives

Creating legal documents

Decisions related to aging and the end of life

Durable power of attorney

Living wills

Overview of health care documents

Overview of legal documents

End notes

 1 Flannery, Michael T. How to Advocate If You’re a Long-Distance Healthcare Proxy. Cake.com

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