Sec. 4. As used in this chapter, "health service provider" refers to:
(1) a psychiatrist or physician who is licensed under IC 25-22.5;
(2) a psychologist who is licensed under IC 25-33;
(3) an individual who holds a license under IC 25-23.6; or
(4) an advanced practice registered nurse (as defined in IC 25-23-1-1) licensed under IC 25-23;
who provides medical services or treatment to an individual. This definition excludes an individual described in subdivision (1), (2), (3), or (4) whose sole service to the individual is to provide a verification letter for a fee.