This guide sets out the law governing medical decisions for people who cannot make them, from the constitutional foundation through the practical mechanics of documents, surrogates, and disputes. Part one covers the right to refuse treatment and the limits the Supreme Court has placed on it, and part two covers capacity — what it means, who determines it, and the errors that recur. Part three covers the instruments: proxies, living wills, POLST, and out-of-hospital DNR orders, with the execution requirements that make each valid or void. Part four covers surrogate hierarchies where no document exists, and part five covers the decision standards a surrogate must apply. Part six covers disputes among family members and between family and clinicians, including medical futility. Part seven covers hospice, palliative care, and how end-of-life care is actually paid for. Part eight covers records access, organ donation, and post-death authority. Worked examples and comparison tables run throughout, and the guide closes with drafting and counseling points for both lawyers and families.