Until the last few years, many school systems were reluctant to evaluate a child with ADHD. But recent laws have made clear the school's obligation to the child suspected of having ADHD that is affecting adversely his or her performance in school. If the school persists in refusing to evaluate your child, you can either get a private evaluation or enlist some help in negotiating with the school. Help is often as close as a local parent group. Each state has a Parent Training and Information (PTI) center as well as a Protection and Advocacy (P&A) agency.
Never forget the cardinal rule  you are your child's best advocate.