We analyze the rhetorical strategies of "digital anti-vaccination churches." We argue that these groups adopt the appearance of a religious institution to gain access to vaccine exemptions, through a process we call "religious masking." Religious masking involves the impersonation of religious style and substance to "pass" convincingly as a religious institution under legal requirements. Simultaneously, the performance of masking also signals to audiences that the church functions as an anti-vaccine exemption resource. Anti-vaccination churches effectively speak to multiple audiences by drawing upon rhetorical strategies of style, consubstantiality, and agency.