Maryland Code, Human Services § 1-208

(1) a minor, if the information requested concerns treatment to which the minor has the right to consent and has consented under Title 20, Subtitle 1 of the Health--General Article;

(2) a parent, if the parental rights of the parent have not been terminated;

(3) a guardian, custodian, or representative of a minor, designated by a court, if authorized to act on behalf of or instead of a parent; or

(4) an individual authorized to act as a surrogate for a parent or guardian in accordance with the federal Individuals with Disabilities Education Act.