Kaiser says that the Mental Health Parity and Addiction Equity Act of 2008 requires that health plans’ mental health services be at least as generous as medical/surgical services. But while that provides financial protection for consumers, access to in-network providers is still problem.

While the problem exists for more plans than those on the ACA marketplaces, the study finds that high demand for services, a shortage of practitioners and low insurance reimbursement rates have all contributed to an atmosphere on provider networks that make mental health care providers reluctant to join.

And while narrow networks, those that usually have less than 25 percent of participating doctors and other health providers in the area, have been adopted by many insurers to help keep marketplace plan premiums lower, they can make the problem of finding mental health services even bigger.

The study also analyzed the average network participation of primary care providers in marketplace plans to compare with the participation of mental health care providers. It found that the average network for ACA plans included 24 percent of all primary care providers in a given market, more than twice the proportion of mental health care providers.