When it comes to your health, staying in control of your future is one of the most important steps you can take. Medical treatment decision-making is the legal process of ensuring that if you ever lose the ability to communicate, your healthcare preferences are still followed. In Victoria, the law allows you to formally appoint someone you trust to act on your behalf. By appointing a medical decision maker in Victoria, you ensure that a person who understands your values and quality-of-life preferences is the one speaking with doctors on your behalf. This legal safeguard provides clarity for medical professionals and prevents your family from having to make harrowing guesses during a crisis.
Understanding Medical Decision Making
Medical decision-making is a legal framework to protect your autonomy. It sets up a “Plan B” for your healthcare. If you become unable to decide or communicate due to an accident, stroke, or degenerative illness, the law identifies who should decide for you.
This is where substitute decision-making comes into play. It is the legal principle where another person is authorised to make a choice that you would have made for yourself. This process only “switches on” when a medical professional determines that you currently lack the decision-making capacity for a specific treatment. It is a protective measure, ensuring that even when you cannot speak, your right to refuse or consent to treatment remains intact through your chosen representative.

Who Can Make Medical Decisions in Victoria?
In Victoria, there is a clear legal hierarchy for who can make decisions for you if you haven’t formally appointed someone. However, relying on the default hierarchy can sometimes lead to family conflict or the appointment of someone who may not truly understand your wishes.

The law prioritises a substitute decision maker for medical decisions in the following order:
- An Appointed Medical Treatment Decision Maker: This is the person you have legally chosen and documented while you had capacity.
- A Guardian appointed by VCAT: If the Victorian Civil and Administrative Tribunal has made an order regarding guardianship and administration in Victoria.
- The Statutory Substituted Decision Maker: If no one is appointed, the law looks to a spouse/domestic partner, then a primary carer, then adult children, and so on.
By taking the initiative now, you override the default list and ensure the person you trust most holds the legal power.
Medical Treatment Laws in Victoria
The legal landscape changed significantly with the introduction of the Medical Treatment Planning and Decisions Act 2016. These medical treatment laws in Victoria were designed to make the system more person-centred. Under this framework, medical professionals must seek consent before performing most procedures.
These medical treatment consent laws require that any decision made by a substitute must be what they believe you would have wanted. It isn’t about what the decision-maker thinks is best; it is about what you would have chosen. This consent to medical treatment law ensures that your “prior preferences” (often documented in an Advance Care Directive) are the primary consideration for doctors and your representative alike.
Don't leave your medical decisions to chance. Talk to our Victorian experts.
Appointing a Medical Decision Maker
The process to appoint a medical decision maker in Victoria is straightforward but requires strict adherence to legal formalities to ensure the document is valid.
- Choose Your Person: Select someone who is over 18, has decision-making capacity, and is willing to take on the role.
- Discuss Your Values: This is the most important step. They need to know your views on life support, pain management, and religious or cultural requirements.
- Formal Documentation: You must complete a formal "Appointment of Medical Treatment Decision Maker" form.
- Witnessing: The document must be signed in front of two witnesses. One must be a registered medical practitioner (like your GP) or a person authorised to witness affidavits (like a lawyer).
At VK Lawyers, we guide you through this paperwork to ensure it meets all the requirements of the Medical Treatment Planning and Decisions Act.
Guardianship vs Medical Decision Maker
It is common to confuse these two roles, but they serve different purposes under guardianship and administration in Victoria.
- Medical Decision Maker: This is a person you choose specifically for healthcare decisions. You can appoint them yourself without going to court.
- Guardianship: A Guardian is usually appointed by VCAT (the Tribunal) when a person has already lost capacity and hasn't made a prior appointment.
When comparing guardianship vs medical decision maker, the latter is always the preferred option because it represents your personal choice rather than a court-imposed decision.
It is a proactive tool that keeps control in your hands.
How We Can Help
Navigating medical treatment laws in Victoria can feel daunting, especially when thinking about a future where you might be vulnerable. Our role at VK Lawyers is to simplify the legalities and provide you with a secure framework for the future.
We help you with:
- Tailored Advice: Explaining how the laws apply to your specific health or family situation.
- Document Preparation: Drafting clear, legally binding appointments and Advance Care Directives.
- Dispute Resolution: Assisting families when there is a disagreement about who should be making decisions.
- VCAT Representation: Providing support if a guardianship matter needs to be heard by the Tribunal.
Our goal is to provide a humanised service that values your dignity and ensures your future healthcare is exactly as you intend it to be.

Reach out to VK Lawyers today for clear, professional advice on medical decision-making and protecting your legacy.
Frequently Asked Questions
Can I appoint more than one medical decision maker?
In Victoria, you can appoint a primary decision-maker and then an "alternative" decision-maker. However, only one person can act at a time. This prevents conflicting instructions from being given to doctors.
What is an Advance Care Directive?
This is a document where you write down your specific instructions or "instructional directives." While a medical decision maker makes the choices, the Directive tells them exactly what those choices should be (e.g., "I do not want a blood transfusion").
What happens if I move interstate?
Medical laws differ between states. If you move from Victoria to NSW or Queensland, you should have your documents reviewed by a lawyer in that state to ensure they remain valid under local laws.
Can my medical decision maker make financial choices for me?
No. A medical decision maker only has power over healthcare and personal care. To allow someone to manage your bank accounts or sell property, you need to sign a separate document called an Enduring Power of Attorney.
When does the appointment start?
The power only begins if you lose the capacity to make a specific medical decision. As long as you are capable of understanding the treatment and communicating your choice, you remain the sole decision-maker for your own body.








