Assistive technology service providers help individuals with disabilities acquire and use appropriate Assistive Technology (AT) to help them participate in activities of daily living, employment and education. There are few pre-service programs that offer degrees or certificates explicitly in assistive technology service provision. In the United States, only three institutions have such accredited programs: University of Illinois Chicago, University of Pittsburgh, and University of Wisconsin-Milwaukee. The programs at University of Illinois Chicago and University of Wisconsin-Milwaukee are graduate certificates; the University of Pittsburgh's is a master's degree. Rather than consisting entirely of individuals with explicit AT education, the field of AT service provision consists of an interdisciplinary group of rehabilitation engineers, occupational therapists, physical therapists, speech-language pathologists, suppliers, educators and other professionals who specialize in AT. AT professionals typically have a degree in one of these other fields, but will have additional training in assistive technology. Professional organizations for AT service providers include: the Rehabilitation Engineering and Assistive Technology Society of North America (RESNA), AAATE (Association for the Advancement of Assistive Technology in Europe (AAATE), ARATA (Australian Rehabilitation and Assistive Technology Association (ARATA), and Rehabilitation Engineering Society of Japan (RESJA). Since the profession includes people with such varied backgrounds, beginning in 1995, RESNA developed several certification programs for recognizing a demonstrated level of professional competence in the service provision of assistive technology: Assistive Technology Professional (ATP) - A service provider who analyzes the needs of consumers with disabilities, assists in selection of appropriate assistive technology for the consumer's needs, and provides training in the use of the selected device(s). Seating and Mobility Specialist (SMS) - An ATP who specializes in the comprehensive seating, positioning, and mobility needs of consumers with disabilities. Rehabilitation Engineering Technologist (RET) - A person who applies engineering principles to the design, modification, customization and/or fabrication of assistive technology for persons with disabilities. An individual must obtain the ATP credential prior obtaining the RET credential. Credentialed service providers must meet specific education and professional experience levels, and must demonstrate knowledge of assistive technology, as shown by passing a credentialing exam. According to RESNA, several thousand individuals hold these credentials. Assistive technology service providers may specialize in several areas of assistive technology, including job accommodations, computer accessibility, vehicle modifications, architectural modifications and home modifications, augmentative and alternative communication, environmental controls, positioning devices, seating and mobility, sensory aids, and learning accommodations. They may be affiliated with hospitals, state vocational