Md. Code, Alc. Bev. & Cannabis § 10-2702

(a) A person may not sell or provide directly or indirectly alcoholic beverages to an individual under the age of 21 years for the individual’s own use or for the use of any other person. (b) A defendant may not be found guilty of selling alcoholic beverages to an individual under the age of 21 years if: (1) the individual willfully represented that the individual is at least 21 years old and obtained an alcoholic beverage; and (2) the defendant proves at the trial that: (i) misrepresentation of age occurred; (ii) due caution was used in ascertaining the age of the individual before providing the alcoholic beverage to the individual; (iii) in the exercise of due caution, the defendant was deceived by the use of documentary evidence; and (iv) because of the use of documentary evidence, the defendant was unable to ascertain that the individual was under the age of 21 years. (c) The City Council may provide by ordinance that a violation of this section is a municipal infraction. (d) The granting of probation before judgment to a license holder or an employee of the license holder for a violation of this section does not bar the Board from proceeding administratively against the license holder for the violation.