The Hospice, Palliative Care, and Life-sustaining Treatment Decision-making Act (hereafter referred to as “Lifesustaining Treatment Decision-making Act”) will come into effect on August 4, 2017. While drafted after prolonged public debate, the Life-sustaining Treatment Decision-making Act still failed to sufficiently discuss how to respect the right to self-determination of people with disability, when making decisions relating to life-sustaining treatment. In an effort to improve this legislation, this paper articulates the viewpoints established in other legal documents, such as the Convention on the Rights of Persons with Disabilities and the Act of the Prohibition of Discrimination against Disabled Persons of United Nation (UN), relating to self-determination of people with disabilities. It further discusses the practical need for supported decision-making, for patients with disabilities considering life-sustaining treatment decisions.