Certification of a service provider, in any field, is the process by which a non-governmental agency or association validates an individual’s qualifications and knowledge in a defined functional or clinical area. Candidates for certification typically must meet specific requirements to be eligible for certification, and those declared eligible must pass an examination. RESNA offers national certification for three specialties: Assistive Technology Professional (ATP), Seating & Mobility Specialist (SMS), and Rehabilitation Engineering Technologist (RET).