A recent change in federal policy could lead many more families affected by autism to gain insurance coverage for applied behavior analysis, advocates say.

In a major shift, the U.S. Office of Personnel Management said that it has determined there is enough evidence behind the use of ABA therapy to deem it a medical rather than an educational service.

The office is responsible for managing benefits for federal government employees, so the announcement paves the way for health plans offered to government workers to include coverage for the popular autism therapy for the first time.

What’s more, autism advocates say it sets an important precedent since the U.S. government is the nation’s largest employer.

“The OPM decision directly contradicts a long-standing insurance industry claim that ABA therapy is not ‘medical,’ but rather ‘educational’ — provided by the schools at taxpayer expense,” said Peter Bell, executive vice president for programs and services at Autism Speaks. “Now, tens of thousands of families will have better access to more affordable, critical ABA treatment.”

Currently, 30 states require that health insurance plans include ABA therapy, according to Autism Speaks, which has lobbied heavily for such legislation.

Under the new rules, coverage for ABA therapy may be included in health plans provided to federal workers starting in 2013.