Section 334.418 - Certificate required to practice, not required, when1. Except as provided in subsection 2 of this section, no person shall practice as an anesthesiologist assistant unless the person holds a current, valid certificate of registration issued pursuant to sections 334.400 to 334.430 to practice as an anesthesiologist assistant.2. The provision of subsection 1 of this section shall not apply to the following: (1) A person participating in a training program leading toward certification by the National Commission for Certification of Anesthesiologist Assistants, as long as the person is supervised by an anesthesiologist;(2) An individual participating in a hospital residency program in preparation to practice as an anesthesiologist; and(3) Any person who is otherwise authorized by subsection 2 of section 334.428 to perform any of the activities that an anesthesiologist assistant is authorized to perform.