34 C.F.R.  §300.552.  Placements.

In determining the educational placement of a child with a disability, including a preschool child with a disability, each public agency shall ensure that--

(a) The placement decision--

(1) Is made by a group of persons, including the parents, and other persons knowledgeable about the child, the meaning of the evaluation data, and the placement options; and
(2) Is made in conformity with the LRE provisions of this subpart, including Secs. 300.550-300.554;

(b) The child's placement--

(1) Is determined at least annually;
(2) Is based on the child's IEP; and
(3) Is as close as possible to the child's home;

(c) Unless the IEP of a child with a disability requires some other arrangement, the child is educated in the school that he or she would attend if nondisabled;
(d) In selecting the LRE, consideration is given to any potential harmful effect on the child or on the quality of services that he or she needs; and
(e) A child with a disability is not removed from education in age- appropriate regular classrooms solely because of needed modifications in the general curriculum.