JEFFERSON CITY, Mo. (AP)--The Missouri Senate gave initial approval Wednesday to legislation that would require insurance providers to cover treatments for autistic children.

The measure would require insurance companies to pay up to $55,000 for behavioral treatment until an autistic child reaches the age of 21.

Autism is a broad term used to describe a spectrum of neurological disorders that affect about 1 out of 110 children in the United States, according to the federal Centers for Disease Control and Prevention. The advocacy group Autism Speaks said 15 states already have laws requiring coverage of medically necessary autism services such as behavioral therapies.

Coverage of autism treatment isn't currently required in Missouri.

The insurance industry says the legislation will increase insurance costs by around 3 percent. Sen. Scott Rupp, the bill sponsor, said studies of states that have required insurance companies to cover the treatment showed less than a 1 percent increase.

Small businesses could apply for a waiver if they can prove offering autism coverage increases the cost of their policy by 2.5 percent in one year.