California HMO regulators this week said insurers must pay for certain autism treatments, but stopped short of forcing them to cover a form of behavioral therapy at the center of a long-brewing fight between parents and their health plans. The therapy in question is a one-on-one form of early intervention that reinforces communication skills and appropriate behavior while discouraging destructive or negative behavior. While widely accepted as beneficial to children with autism, the therapy can cost $36,000 to $75,000 a year, and insurers have argued it's an educational, not a medical, service.