The Law Requires LRE
The federal Individuals with Disabilities Education Act (IDEA) mandates that students with disabilities receive a free appropriate public education (FAPE) in the least restrictive environment (LRE). Specifically, the law states: "to the maximum extent appropriate, children with disabilities, including children in public or private institutions or other care facilities, are educated with children who are not disabled, and special classes, separate schooling, or other removal of children with disabilities from the regular educational environment occurs only when the nature or severity of the disability of a child is such that education in regular classes with the uses of supplementary aids and services cannot be achieved satisfactorily."
What It Really Means
Basically, what this means is that students with disabilities must not be needlessly separated from their non-disabled peers during the school day. It also means they must be allowed to receive educational and related services in settings with their non-disabled peers to the maximum extent that they can do so while having their unique individual needs met. In other words, disabled students should only be educated separately from their non-disabled peers when doing so would prevent them from receiving an appropriate education. The term least restrictive environment is used to describe the degree of inclusion students with disabilities experience during the school day (i.e., the extent to which they are included in activities with non-disabled peers).
Rationale for the Least Restrictive Environment
The reason a requirement for disabled students to be educated in the least restrictive environment exists is that prior to the passing of Public Law 94-142 (Education for All Handicapped Children Act) in 1975—the predecessor law for IDEA— students with disabilities were routinely segregated and isolated from non disabled students. In "The Least Restrictive Environment: Its Origins and Interpretations in Special Education," Jean Crockett and James Kauffman explain that special classrooms were typically "in basements, down dark hallways, and in former closets or somewhere at the back of the main school building." Special education classrooms were also often placed in trailers outside the main school building. During this time, students with disabilities had virtually no contact with their non disabled peers—not even during lunch, recess, or resource classes such as art and music. These unfortunate practices prevented both disabled and non disabled students from learning with, about and from each other.
Deciding What Is Best for the Student
What constitutes the least restrictive environment for a particular child is highly dependent upon the nature and severity of that child's disabilities and the resources, supports and aids his/her IEP (individualized education program) team determines is appropriate for him/her. So what may be considered the least restrictive environment for one child may not necessarily be considered the least restrictive environment for another child, even if they have the same disability.
When making placement decisions, IEP teams must consider the child's needs first before deciding which of a continuum of special education placements would be appropriate for the child. The continuum of special education placements includes regular education with weekly monitoring from a special education teacher, regular education with daily consultation from a special education teacher, regular education with special education services and supports which are aligned with the general education curriculum, regular education with special education services provided for part of the day in a resource room or a special education classroom, self-contained special education classroom, therapeutic day school, residential school or treatment facility, hospital, detention facility or home instruction.
Crockett, Jean and Kauffman, Martin. The Least Restrictive Environment: Its Origins and Interpretations in Special Education. Lawrence Erlbaum Associates Inc., 1999.
SPED Watch, The Least Restricitve Environment, https://www.spedwatch.org/files/lre.pdf