A new bill aims to change that.
HB1940 would get rid of the age limit altogether, requiring insurance companies to cover anyone with autism.
"Autism certainly isn't cured by six," says Mark Llobell, with the Va. Autism Project.
He's seen the benefits of intensive treatment first-hand.
At four, his grandson was completely nonverbal. Now at age 10, he's in public school. Instead of 40 - 50 hours of Applied Behavior Analysis therapy a week, he only needs six to eight.
Treatment doesn't come cheap, though. It can cost $50,000 a year. Insurance covers up to $35,000, but that's still only for the limited age range of two - six.
"There's no other medical illness or malady that a child can develop that has an age cap," Llobell said, "For instance, if a child has MS or diabetes or AIDS or cancer, it's not like at 6 years old they say 'Sorry, we can't help you any longer,' and our children with autism should have that same type of coverage."
Critics say expanded coverage will be expensive. Llobell argues their cost estimates are inflated.
For now, the first hurdle to get the bill passed is the House Commerce and Labor committee.
A vote is expected to take place Thursday.
To contact your lawmakers about the bill, click here to find their contact information.