Vol. 24 Annals of Health Law 304
Agency refers to a legal relationship whereby one person acts for or represents another by the latter’s authority.174 The agency relationship is a fundamental legal concept that is relevant to those situations wherein the PA
acts on behalf of the supervising physician.175 Agency authority may be apparent or inherent.176 When apparent, the agent’s authority is communicated
to the third party by written or spoken words, or any other conduct of the
principal which reasonably causes the third person to believe the principal
consents to have the act done on his behalf by the person purporting to act
for him.177 Under inherent agency power, the power of the agent is derived
solely from the agency relationship and exists for the protection of persons
harmed by or dealing with the agent.178 Authority also may either be express, in which authority is directly granted upon the agent in express terms,
or implied, in which the authority is necessary, usual, and proper to accomplish or perform the main authority expressly delegated to the agent.179
Under the theory of apparent authority, a principal-physician holds out
an agent-PA as one who possesses certain authority, in a way that would
cause or allow a third party to believe the agent possesses such authority.180
Principals that employ PAs have a legal duty to their prospective patients to
provide care.181 Most state laws restrict a PA’s scope of practice to the supervising physician’s scope of practice.182 However, AAPA’s model legislation and the PA regulations in Maine provide that the PA’s scope of practice may exceed the physician’s scope so long as adequate provisions for
consultation and referral are in place.183
In general terms, the most practical decisions about scope of practice are
made at a level where the needs of the individual patient can be best evalu-
175. Gara & Davis, supra note 14, at 743.
176. See generally STATE LAWS 14TH ED., supra note 101 (referring to each state’s provisions on scope of practice. As of 2014, twenty-five states and the District of Columbia allow the parameters of scope of practice to be determined at the practice site).
177. Gara & Davis, supra note 14, at 742.
178. See BLACK’S LAW DICTIONARY 62 (6th ed. 1990) (“ A relationship between two
persons, by agreement or otherwise, where one (the agent) may act on behalf of the other
(the principal) and bind the principal by words and actions.”).
180. BLACK’S, supra note 173, at 96.
181. David J. Bissonette, The Derivation of Authority For Medical Order Writing by
PAs, 4 J. AM. ACAD. PHYSICIAN ASSISTANTS 358, 361 (1991).
182. ALASKA ADMIN. CODE tit.12, § 40.430. See generally AM. ACAD. OF PHYSICIAN
ASSISTANTS, STATE LAWS AND REGULATIONS (14th ed., Rev. 2014) (referring to states limiting PA scope of practice to the supervising physician’s scope of practice).
183. 02-373-2 ME. CODE R. §6. See also AM. ACAD. OF PHYSICIAN ASSISTANTS, MODEL
STATE LEGISLATION FOR PHYSICIAN ASSISTANTS 2 (2013), available at