ALBUQUERQUE, N.M. — The investigative arm of the U.S. Department of Health and Human Services has agreed to review the level of access that New Mexicans have to behavioral health care services through the Medicaid program.

Members of New Mexico’s congressional delegation made the request earlier this year, citing significant access issues that remain following a shake-up among nonprofit providers who served some of the state’s most needy residents.

The inquiry will be one of a handful being conducted by the agency’s inspector general.

New Mexico’s behavioral health system was upended in 2013 when Republican Gov. Susana Martinez’s administration froze payments to 15 nonprofits after an audit identified $36 million in Medicaid overpayments and raised concerns about possible fraud and abuse.

Some providers were forced to close. Others were replaced by out-of-state companies, some of which have since left the state.

An investigation by the New Mexico Attorney General’s Office eventually found only regulatory violations and no patterns of fraud among the nonprofits.

New Mexico’s congressional delegates pointed to recent settlements that show the initial audit was incorrect. Several providers settled overpayments with the state at a fraction of what was estimated they owed.

The governor’s office argued Friday that at least $9.4 million in overpayments were incurred by the providers and less than half of that has been returned to the state so far. Hearings involving some of the providers are stilling pending, so state officials say the total amount of overpayments could increase.

Joe Cueto, a spokesman for the governor, also said more New Mexicans than ever before are receiving mental health care and substance abuse services.

The state Human Services Department reported last year that the number of residents accessing behavioral health services through government-funded programs had increased nearly 5 percent over a year’s time. That added to a surge that began with the expansion of Medicaid eligibility in 2014.

“We’ll continue to do all we can to safeguard taxpayer dollars to ensure funds are going to help those who need it the most,” Cueto said.

U.S. Democratic Sens. Tom Udall and Martin Heinrich called it a manufactured crisis that has had tragic consequences for residents dealing with mental illness and other behavioral health issues.

“Our fragile network of behavioral health providers is still struggling to meet the needs of these patients,” Udall said in a statement.

U.S. Rep. Ben Ray Lujan, D-New Mexico, said he’s hopeful the results of the study can be used to improve the system.

The inspector general’s office outlined its plans in a letter sent to the delegates in late June. The letter was made public Friday.

The review will cover the extent to which behavioral health providers are included in the states’ managed care plans and what types of services are offered by the providers.

Available appointment times, waiting lists and the ability of providers to make referrals also will be examined as the inspector general looks to identify ways to improve care for Medicaid patients in New Mexico and the other four states.

The review is expected to begin in the fall.