Roughly two-thirds of Americans with a diagnosed mental health condition were unable to access treatment in 2021, though they had health insurance. And only a third of insured people who visited an emergency department or hospital during a mental health crisis, received follow-up care within a month of being discharged.

These are among the findings of a new report by the actuary firm Milliman, released Wednesday. The mental health advocacy group, Inseparable, commissioned the report and also released an accompanying brief offering policy solutions to address the gaps in mental health care.

"We kept hearing nightmare stories about Americans not getting the treatment that they needed because insurance companies were denying them care," says Bill Smith, founder of Inseparable. "But we didn't have enough data to show just how extensive and deep the problem was."

The report is "illuminating" and timely, says Meiram Bendat, a psychotherapist and an attorney, who wasn't involved in writing it. "We're dealing with an issue that [is] on top of mind for nine out of ten people."

While the overall findings aren't surprising, "it is striking that the access impediments remain what they are," adds Bendat who founded PsychAppeal, a law firm focused on mental health insurance advocacy. Those barriers include a workforce shortage, poor reimbursement rates for providers, and "substandard enforcement" of consumer protections and laws requiring that insurance companies cover mental health conditions.

"The data confirm what so many families and our friends know, which is that mental health access is a problem," says psychologist Benjamin Miller, one of the authors of the accompanying policy solutions brief. "It's very clear that there are people who have identifiable conditions, who are not able to find providers to help them."

The Milliman report, which used a range of publicly available surveys as well as proprietary health insurance claims data, found that nearly a quarter of people with insurance – Medicaid, commercial insurance and Medicare – had at least one mental health diagnosis in 2021.

Many of those people don't get treatment. Among the roughly half of Americans who are covered with commercial insurance, only about 30% of those with a mental health or addiction diagnosis got connected to a behavioral health specialist.

People on Medicaid with such diagnoses were the most likely to see a mental health care provider, with about 44% getting care. Only about 15% of those on Medicare got care for their diagnoses.

That's an "astonishing gap" in mental health coverage, says Smith. "Across the board, the numbers aren't great."

The gap in mental health treatment, "won't close unless private insurance companies" take steps to increase access to mental health care, he says. "We have a long way to go."

The report also finds that over half of the U.S. population lives in areas designated as Mental Health Professional Shortage Areas, and that the country has less than a third of the psychiatrists needed to meet those provider shortages.

"We have not moved the needle on increasing availability of our workforce," says Miller. "I've been using the same data point for about ten years that half the country lives in a mental health provider shortage area. And it hasn't changed."

In their report, Miller and his colleagues offer concrete policy solutions to address the workforce shortage and coverage gaps in insurance plans, including expanding the use of telehealth and use of peer support specialists.

The authors also suggests providing "competitive reimbursement rates" for mental health care professionals

Another report by Milliman published in 2019 had found that mental health care providers are reimbursed at lower rates than physical health providers. "We've known for a long time that there is under-reimbursement of care," says Bendat.

Addressing that disparity in payment would help prevent health care worker burnout and ensure more mental health providers are in-network to care for the growing number of people in need.

The Inseparable solutions report also recommends that insurance companies be mandated to provide up-to-date accurate directories for in-network providers.

"The problem with these in-network directories is that when you begin to call around and you begin to ask people, 'Can you see me? Are you accepting new patients?' The answer to a lot of them is no, they're not accepting new patients," says Miller. "Some provider directories are old enough that you might even have people on there that are not practicing anymore."

But requiring health plans to cover out-of-network care is also crucial, say Miller and his colleagues.

"The insurance company should pay that cost to cover your care regardless of whether or not it's in their network or not," says Smith. "It's a huge problem when you have people that are making decisions about their health and the safety of their families and doing that from a place of scarcity."

As the Milliman report finds, the average out-of-pocket cost for an hour-long psychotherapy session in 2021 was $174, which is a huge barrier to access.