Certified Professional: An individual who holds the ATC (Athletic Trainer, Certified) credential and is in good standing.
Associate: An individual, not ATC credentialed or a state licensed Athletic Trainer, who is working in athletic education, research, medicine or other professions related to athletic training. A certified member whose certification is no longer in good standing with the BOC is changed to an Associate member.
Certified Student: A certified individual enrolled as a full time graduate student working towards an advanced degree at an accredited college or university.
Student: An individual enrolled as a full-time student in a college or university who has not fulfilled BOC requirements for certification.
https://www.nata.org/membership/about-membership/member-categories