SB 770 – This act creates the Missouri Scholarship for Students with Developmental Disabilities Program. Parents of children with certain developmental disabilities who are dissatisfied with their children's progress in public school may be eligible to receive a scholarship to enroll their children in a participating private school or other public school of choice. To be eligible, the child must be enrolled in public school for the prior year and have obtained admission to a participating private school. The amount of each scholarship shall be the amount of per pupil state funding distributed to the school district under the foundation formula, or the actual cost of tuition, whichever is less. This act requires the adjustment of "weighted average daily attendance" under the foundation formula so that no school district receives state aid for a student that receives a scholarship and enrolls elsewhere. This act grants rulemaking authority to the Department of Elementary and Secondary Education to implement this section as described therein. The provisions of this act shall expire in six years but the scholarship will remain in force until the child returns to his or her original public school, graduates from high school, or turns 22, whichever occurs first. MICHAEL RUFF