Amends the Probate Act of 1975. Provides that upon the filing of a petition by a reputable person or by the alleged person with a disability himself or on its own motion, the court may adjudge a person to be a person with a disability, but only if it has been demonstrated by clear and convincing evidence that the person is a person with a disability and the person cannot be supported through a supported decision-making agreement. Provides that at the time of the appointment of a guardian the court shall inform the ward of his right to petition for termination of an adjudication of disability using a supported decision-making agreement. Makes other changes. Amends the Supported Decision-Making Agreement Act. Changes the definition of "principal" to mean an adult (rather than an adult with intellectual or developmental disabilities) who seeks to enter, or has entered, into a supported decision-making agreement with a supporter. Allows a principal to elect to nominate the supporter as the principal's health care surrogate and may act as the principal's health care surrogate when the standards set forth in the Health Care Surrogate Act have been met. Makes conforming changes. Amends the Health Care Surrogate Act. Provides that a supporter designated under a supported decision-making agreement has second priority to make decisions on behalf of a patient.