Notwithstanding any other provision of this subtitle, a judgment in an action under this subtitle is not binding or conclusive on: (1) The State, unless individually joined as a party to the action and State law authorizes the judgment to be binding or conclusive as to its interests; or (2) The United States, unless the United States is individually joined as a party to the action and federal law authorizes the judgment to be binding or conclusive as to its interests.
Maryland Legal Code