Beginning on 1 January 2014, French pharmacists are now legally permitted to substitute a biosimilar for the prescribed (reference) biological medicine as long as the prescribing physician has not marked the prescription as “non-substitutable.” According to the new law, substitution is allowed only when initiating a course of treatment, and if the biosimilar belongs to the same group as the prescribed product, known as a “similar biologic group.” The criteria for inclusion in a “similar biologic group” have yet to be defined by the French healthcare authority (ANSM).