For those that apply for the Addiction Certification Board CFAP in the United States,

The CFAP is an add-on certification for those who are already licensed in practice or employment; you must be an active, licensed Health Care Professional, i.e., MD, DO, Ph.D., PsyD, Ed.D, LCADC, LPC, LCSW, LMFT, Advanced Practice Nurse (APN), Licensed Nutritionist or Dietician.