34 C.F.R. § 300.141 – Requirement that funds not benefit a private school.

(a) An LEA may not use funds provided under section 611 or 619 of the Act to finance the existing level of instruction in a private school or to otherwise benefit the private school.
(b) The LEA must use funds provided under Part B of the Act to meet the special education and related services needs of parentally-placed private school children with disabilities, but not for meeting—
1. (1) The needs of a private school; or
2. (2) The general needs of the students enrolled in the private school.
  (Approved by the Office of Management and Budget under control number 1820-0030)
  (Authority: 20 U.S.C. 1412(a)(10)(A))