The proposed partnership between UNC Health Care and Atrium Health, formerly known as Carolinas HealthCare System, is now drawing the attention of North Carolina’s attorney general.

Democratic Attorney General Josh Stein sent a letter on Thursday requesting information from leadership of each hospital system regarding the potential new venture.

The proposal has been negotiated almost entirely behind closed doors, which has led to questions and frustration from the UNC System Board of Governors – which has set up a special committee to review any possible deal – and North Carolina’s treasurer.

Stein requested varying information in Thursday’s letter to judge the proposal’s “impacts on health care prices, choices for patients and insurers, and other information that will allow him to determine whether or not this deal will harm North Carolinians.”

Stein’s request seems to be based off of concerns he shares with North Carolina Treasurer Dale Folwell in that a merger could lead to increased costs for health care in North Carolina.

Folwell asked UNC Health Care officials to take out a $1 billion performance bond earlier this week, which would guarantee health care costs don’t go up under any new partnership. Folwell’s office does not have the authority to force UNC Health Care to take that action. Officials with the hospital system issued a statement after Folwell’s request saying that UNC Health Care does not “control inflation or other variables associated with the cost of care.”

“My priority is to look out for North Carolina’s health care patients,” Stein said in Thursday’s release. “When large health systems merge, patients and businesses often end up paying more. I intend to make sure that doesn’t happen here.”

Stein met with leadership from UNC Health Care and Atrium when the two announced intentions to form a new partnership last summer, according to the release. But state officials have “received little information about the proposed combination, making conducting a review impossible.”

Carolinas HealthCare made headlines last week when it was announced the system would change its name to Atrium Health. Atrium then announced intentions to merge with a Georgia-based health care system.

Stein set a March 16, 2018, deadline for the requested information to be turned over to his office.

UNC Health Care issued the following statement regarding Stein’s request:

“We look forward to working with North Carolina Attorney General Josh Stein and the Department of Justice in providing the information requested in a timely and transparent manner.

We are still in discussions with Atrium Health on the proposed partnership. UNC Health Care’s goals in pursuing this partnership are to improve the health of all North Carolina’s citizens, increase access to much-needed medical care and reduce rising costs.”

There is no timeline for when any proposed partnership between UNC Health Care and Atrium could be finalized.