A re-evaluation should be conducted automatically every three years according to the Federal (IDEA’04) and State Law (PA Regulations and Standards) for every child who qualifies for special education services and/or supports. However, in PA if your child has mental retardation – then the child must be re-evaluated automatically every two years (§14.124).
In addendum, if you feel that your child’s program and/or placement is inappropriate and a re-evaluation needs to be conducted in order for your child to receive an appropriate education you can request for it to be done sooner, you should:
Make sure you put the date on your request.
Keep a copy for your archives.