After officials in the last holdout state enacted a new rule, all 50 states and Washington, D.C. have mandates that require some level of insurance coverage for the treatment of autism.

The Tennessee Department of Commerce and Insurance now requires all individual, small and large group insurance plans issued in the state to cover treatment for autism that is medically necessary and appropriate and is not experimental, including applied behavior analysis, or ABA, at the same level as any other medical condition.  Before the new rule was issued in August, insurance companies in the state could define their own mental health benefits, but now they must cover the treatment of autism and any other condition as listed in the Diagnostic and Statistical Manual of Mental Disorders.

The parent-led movement to extend insurance coverage for autism throughout the country started in the early 2000s.