"any item, piece of equipment, or product system, whether acquired commercially off the shelf, modified, or customized, that is used to increase, maintain, or improve functional capabilities of a child with a disability. Exception. - The term does not include a medical device that is surgically implanted, or the replacement of such device." ( § 1401(B)).

Children from age 2 to 22, have the role or occupation of being a student, of learning at school and in the world. Assistive Technology services are "any service that directly assists a child with a disability in the selection, acquisition, or use of an assistive technology device." ( § 1401(2)). AT helps bridge the gap between their "job" of being a student, and whatever their disability or need is.