Advance Care Planning in Ontario: Expressed Wishes, Living Wills, and the Law

Most people assume advance care planning means filling out a single form and filing it away. In Ontario, it is something more — and in some ways more powerful. If you want a say in future medical decisions you may not be able to make yourself, understanding how advance care planning in Ontario works under provincial law is where that planning has to start.

It Is a Process, Not a Form

Advance care planning is the ongoing conversation you have — with yourself, your family, your substitute decision-maker (SDM), and your health care providers — about the kind of care you do and do not want if you lose the capacity to speak for yourself.

No single document captures all of it. The process involves thinking through your values (what makes life meaningful to you), learning what kinds of decisions might arise (resuscitation, mechanical ventilation, artificial nutrition), and communicating your answers clearly to the people who will act on them.

The law that gives these conversations legal teeth in Ontario is primarily the Health Care Consent Act and, for personal care broadly, the Substitute Decisions Act.

Expressed Wishes: The Legal Concept That Actually Binds Your SDM

Under the Health Care Consent Act, when a person lacks capacity to make a health care decision, their substitute decision-maker steps in. But the SDM is not free to decide however they like. The Act establishes a strict hierarchy:

1. If you expressed a wish while you were capable — a prior capable wish — your SDM must follow it, provided it is applicable to the circumstances.
2. Only if there is no applicable prior capable wish does the SDM fall back on acting in your best interests.

This is the expressed-wishes framework, and it is significant. A prior capable wish is not a suggestion. If you told your SDM, while you had capacity, that you did not want mechanical ventilation in a condition of permanent unconsciousness, your SDM is legally required to refuse that treatment on your behalf — even if they personally would make a different choice.

The wish does not need to be written down to count. An oral statement made to your doctor or your family can qualify. That said, a written record is far more reliable. Memories fade, and disputes about what you "really meant" are avoidable.

What a Living Will Is — and Why Ontario Treats It Differently

The term "living will" is widely used, but Ontario does not have a statute by that name. Some Canadian provinces and many US states have formal advance directive legislation with prescribed forms. Ontario took a different approach: rather than creating a standalone living-will document with its own legal regime, it built the expressed-wishes concept directly into the Health Care Consent Act.

What this means practically is that a document you write — sometimes called a living will, an advance directive, a personal directive, or an advance care plan — carries weight in Ontario not because it is a recognized legal instrument on its own, but because it is evidence of your prior capable wishes. The document is a record, not a self-executing instrument.

This is not a weakness. It is actually flexible. There is no prescribed form you must use. A plain-language letter, a completed values-history worksheet, or a detailed instruction attached to your personal-care power of attorney document can all serve the purpose — as long as the content is clear and you were capable when you expressed it.

How to Record and Communicate Your Wishes

Because Ontario does not require a specific form, the emphasis falls on clarity and communication.

Write it down. A written record of your wishes is far more useful than a verbal statement made years ago. It can be a standalone document or instructions written directly into your personal-care POA. Include the date and sign it. Plain language is better than legal language — write it the way you would explain it to your doctor.

Tell your attorney for personal care. Your personal-care power of attorney names someone to make decisions on your behalf. That person needs to know your wishes. Handing them a document is not enough; talk through what you mean and why. The Substitute Decisions Act governs these attorneys, and the more clearly they understand your values, the better they can apply specific wishes to situations that may not fit neatly into what you wrote.

Tell your health care providers. Your family doctor and, if relevant, your specialist should know your wishes exist and ideally have a copy on file. Some hospitals and long-term care facilities have processes for recording advance care plans in your chart.

Current Wishes Always Come First

One critical rule: your current capable wishes always override your prior expressed wishes. Advance care planning prepares for a future where you cannot speak. If you regain capacity, or if you are capable in the moment, what you say right then is what governs — regardless of what any document says.

The hierarchy exists to protect your autonomy in both directions: your current self controls your current situation, and your past capable self controls your future incapable self. Your SDM does not override either.

What Is Worth Documenting

Not everything needs to be specified — and an impossibly long list of scenarios is hard to apply. Focus on the decisions most likely to arise:

• Cardiopulmonary resuscitation (CPR): Do you want it attempted? Under what circumstances?
• Mechanical ventilation: For a defined period as a bridge to recovery, or not at all?
• Artificial nutrition and hydration: If you are in a permanent vegetative state or have advanced dementia?
• Hospitalization versus comfort-focused care: If you are in a long-term care setting and your condition deteriorates?
• Organ and tissue donation: Registered separately through ServiceOntario (as of writing — verify current registration process), but worth noting in your planning documents as a statement of values.

Be as specific as you can about the conditions under which a wish applies. A wish that says "no heroic measures" is much harder for an SDM and health care team to apply than one that describes what you mean by that phrase.

An Important Limitation

Your expressed wishes bind your SDM, but they do not require a health professional to act contrary to professional standards or applicable law. If a treatment you requested is medically inappropriate in the circumstances, your SDM may not be able to insist on it. Planning documents are most effective when they focus on refusing or limiting treatment rather than demanding specific interventions, and when they are paired with an honest conversation with your doctor about what is realistically possible.

Interaction with Your Personal-Care Power of Attorney

Your personal-care POA and your expressed-wishes document work together. You can include your wishes directly in the POA document itself, or keep them in a separate statement that you reference in the POA. Either approach is valid. The POA names who decides; the expressed wishes tell them how.

If you have a POA but no documented wishes, your SDM falls back on their judgment of your best interests. That may be fine — or it may produce a result you would not have chosen. The two documents together give your SDM both the authority and the guidance they need.

Practical Steps to Take Today

1. Think through your values and priorities before you start writing.
2. Talk to your doctor about the kinds of decisions that might arise given your health history.
3. Choose your attorney for personal care carefully — this person needs to be able to follow your wishes even under pressure.
4. Write down your wishes in plain language, date and sign the document, and attach or reference it in your personal-care POA.
5. Give copies to your attorney, your doctor, and any close family members who might be involved.
6. Review the document after any significant change in health, relationships, or values.

Frequently asked questions