(5) Least restrictive environment.--
(A) In general.--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 use of supplementary aids and services cannot be achieved satisfactorily.
(B) Additional requirement.--
(i) In general.--A State funding mechanism shall not result in placements that violate the requirements of subparagraph (A), and a State shall not use a funding mechanism by which the State distributes funds on the basis of the type of setting in which a child is served that will result in the failure to provide a child with a disability a free appropriate public education according to the unique needs of the child as described in the child's IEP.
(ii) Assurance.--If the State does not have policies and procedures to ensure compliance with clause (i), the State shall provide the Secretary an assurance that the State will revise the funding mechanism as soon as feasible to ensure that such mechanism does not result in such placements.