Who Makes Medical Decisions When a Parent Cannot?

Q: Can my siblings and I all share medical decision-making authority equally?

Generally, no — not without conflict. Healthcare providers typically need to work with one designated decision-maker, and when multiple family members have equal authority or when no legal designation exists, disagreements between siblings can create significant delays in care. A healthcare power of attorney designates one agent precisely to avoid this problem and remove ambiguity when time matters most.

Q: When is the right time to set up these legal documents for a parent?

The right time is before they are needed — which means now, while your parent has capacity and the conversation can happen without the pressure of a crisis. An elder law or estate planning attorney can prepare a healthcare power of attorney, advance directive, HIPAA authorization, and durable financial power of attorney in a single appointment.

7 min read |

June 28, 2026

The answer depends almost entirely on whether the right documents are in place. Here is what families need to understand.

In fourteen years of working with families navigating senior care, I have watched the same moment play out more times than I can count: a parent loses the ability to speak for themselves, suddenly or gradually, and the family discovers they have no clear legal answer to the question of who takes over. The stress of that moment is real. And it is almost entirely preventable.

Understanding how medical decision-making authority works, and putting the right structures in place before they are ever needed, is one of the most important things a family can do. It does not require an emergency. It requires a conversation and an appointment with an attorney.

When Documents Are in Place

The single most reliable way to ensure medical decisions are made well for your parent is to have a healthcare power of attorney and an advance directive in place before they are ever needed.

Healthcare Power of Attorney (HCPOA)

If your parent has executed a healthcare power of attorney, the person they designated as their agent has legal authority to make medical decisions on their behalf when they cannot make those decisions independently. This includes communicating with physicians, authorizing or declining treatments, consenting to procedures, and making decisions about care settings.

The designated agent acts in accordance with your parent’s known wishes where those wishes are documented or expressed, and in their best interest when wishes are unknown. Having a trusted person in this role, and having that role clearly defined legally, is the most reliable way to ensure decisions are made well.

Advance Directive and Living Will

An advance directive, sometimes called a living will, documents your parent’s specific wishes about end-of-life care while they still have the capacity to express those wishes. This typically includes preferences about resuscitation, mechanical ventilation, artificial nutrition, and the conditions under which life-sustaining treatment should or should not be continued.

When an advance directive exists, it provides direct guidance to physicians and the healthcare agent about what your parent would have wanted. It does not replace the healthcare agent; it gives that person and the medical team clear instructions to follow. Perhaps most importantly, it takes impossible decisions out of the hands of family members who may disagree about what their parent would have wanted.

Talk Through the Decisions Before They Are Needed

Documents provide legal authority, but they do not replace conversation. The most effective healthcare agents are not guessing what their parent would want. They already know. Families should talk through scenarios such as:

How aggressive care should be in serious illness
Preferences about quality of life versus life extension
Attitudes toward hospitalization, long-term care, or hospice

In my experience, the families who navigate these moments with the least conflict are not necessarily the ones with perfect legal documents; they are the ones who have had honest conversations while there was still time to have them. Without those discussions, even well-prepared legal documents can leave room for uncertainty and disagreement.

Where the Documents Actually Are and Who Can Access Them

Having the right documents means very little if they cannot be produced quickly when they are needed. Families should ensure that copies of the healthcare power of attorney, advance directive, and HIPAA authorization are:

Easily accessible at home, not locked away in a safe deposit box
Shared with the designated healthcare agent
Provided to primary care physicians and relevant specialists
Available in digital form for quick access during emergencies

In urgent situations, hospitals will not wait for documents to be located. If they are not immediately available, care decisions may proceed without them. I have seen families scramble to find documents during a hospitalization when every minute matters. Do not let that be your family’s experience.

When Documents Are Not in Place

When a parent loses decision-making capacity without a healthcare power of attorney or advance directive, the family’s options narrow considerably, and the path forward becomes harder.

Most states have surrogate decision-making laws that establish a hierarchy of who may make medical decisions when a patient cannot and no legal documents exist. This hierarchy typically begins with a spouse, then moves to adult children, then to parents, then to siblings, and so on. The specifics vary significantly by state.

In practice, this means a family member can often still make decisions through this surrogate pathway. But it does not work cleanly when family members disagree, when the designated surrogate is not available or willing, or when healthcare providers require a formal legal designation before proceeding.

Capacity Is Not Always All-or-Nothing

Loss of decision-making ability is often gradual, not a single clear moment. A parent may be able to make some decisions but not others, or may have good days and difficult ones. Physicians assess capacity based on the specific decision at hand, not a blanket determination that covers everything.

This can create confusion for families, especially when a parent is still expressing opinions but may not fully understand the consequences of a decision. In those situations, the healthcare agent may need to step in selectively, which can feel uncomfortable without prior discussion.

Having early conversations about when the agent should take a more active role helps prevent conflict later, and removes the burden of that judgment call from the agent’s shoulders.

When Family Members Disagree

When siblings or other family members cannot agree about a parent’s care, and no legal document designates a single decision-maker, the situation can become both emotionally and legally complex.

Healthcare providers will sometimes defer to the statutory surrogate hierarchy, but they are not equipped to resolve family conflict. And in my experience, unresolved conflict at the bedside rarely resolves itself.

In those circumstances, guardianship through the courts may become necessary. Guardianship is a legal process in which a court appoints a guardian to make decisions on behalf of a person who lacks capacity. The process requires a legal petition, a judicial hearing, and ongoing court oversight. It takes time, involves attorney fees, and does not always produce the outcomes families expect or want.

It is the outcome that proper planning is specifically designed to avoid.

The HIPAA Piece Families Often Overlook

Federal privacy law limits what healthcare providers can share with individuals who are not directly involved in a patient’s care. While providers are generally permitted to share information with family members who are actively involved in care decisions, many require a written HIPAA authorization before doing so, and having one in place removes all ambiguity about who receives updates, can ask questions, and stays informed throughout the process.

A HIPAA authorization designates the specific individuals who are permitted to receive medical information. Without it, a family member calling a physician’s office may be told that no information can be released. Getting this authorization completed alongside the healthcare power of attorney and advance directive ensures the right people have access to the right information from the start.

Financial Authority Is a Separate Issue

One of the most common, and most disruptive, misunderstandings is assuming that a healthcare power of attorney also gives someone authority to manage finances. It does not.

A separate durable power of attorney for finances is required to:

Pay bills
Manage insurance
Access bank accounts
Handle property or legal matters

Without this document, families may find themselves able to make medical decisions but unable to manage the practical financial responsibilities that support care. The two documents need to exist together.

What to Do Right Now

If your parent still has legal capacity, the single most valuable thing you can do is encourage them to execute a healthcare power of attorney, advance directive, and HIPAA authorization, ideally all in a single appointment with an elder law or estate planning attorney.

If your parent’s capacity is uncertain, consult an elder law attorney before proceeding. A capacity evaluation can be part of the document preparation process. And if your parent has already lost capacity without these documents in place, an attorney can advise on what options remain, including whether guardianship may be necessary.

Do not wait for a crisis to prompt this conversation. In my experience, the families who act before they have to are the ones who are grateful they did.

Frequently Asked Questions

What is the difference between a healthcare power of attorney and an advance directive?

A healthcare power of attorney designates a specific person to make medical decisions on your parent’s behalf if they cannot do so themselves. An advance directive, sometimes called a living will, documents your parent’s specific wishes about end-of-life care while they still have capacity. They serve different but complementary purposes: the HCPOA gives someone authority; the advance directive gives them instructions. Both documents working together provide the clearest possible framework for your parent’s care.

What happens if my parent loses capacity without any of these documents in place?

Most states have surrogate decision-making laws that allow a family member to step in, typically starting with a spouse, then adult children. But this pathway can break down quickly if family members disagree or if healthcare providers require a formal legal designation. Without documents, the family’s options narrow significantly, and consulting an elder law attorney as soon as possible is the right next step.

Can my siblings and I all share medical decision-making authority equally?

Generally, no, not without conflict. Healthcare providers typically need to work with one designated decision-maker, and when multiple family members have equal authority or when no legal designation exists, disagreements between siblings can create significant delays in care. A healthcare power of attorney designates one agent precisely to avoid this problem and remove ambiguity when time matters most.

Does a healthcare power of attorney also give someone authority over my parent’s finances?

No. A healthcare power of attorney covers medical decisions only. A separate durable power of attorney for finances is required to manage bills, insurance, bank accounts, and legal or property matters. Families often discover this gap at exactly the wrong moment, when medical decisions and financial decisions have to happen simultaneously, so it is important to have both documents in place.

When is the right time to set up these legal documents for a parent?

The right time is before they are needed, which means now, while your parent has capacity and the conversation can happen without the pressure of a crisis. An elder law or estate planning attorney can prepare a healthcare power of attorney, advance directive, HIPAA authorization, and durable financial power of attorney in a single appointment.

Sources

National Institute on Aging. Advance Care Planning. https://www.nia.nih.gov/health/advance-care-planning
National Institute on Aging. Advance Care Planning: Advance Directives for Health Care. Last reviewed October 31, 2022. https://www.nia.nih.gov/health/advance-care-planning/advance-care-planning-advance-directives-health-care
CaringInfo / National Alliance for Care at Home. Advance Directives: Forms for Each State and Territory. Updated June 15, 2026. https://www.caringinfo.org/planning/advance-directives
U.S. Department of Health and Human Services, Office for Civil Rights. Health Information Privacy (HIPAA). Updated March 21, 2026. https://www.hhs.gov/hipaa/index.ht

Disclaimer: This CareCircle Insights blog does not constitute medical, legal, or financial advice and is provided for general educational purposes only. Please consult a qualified professional about your specific circumstances.