Jill Hoggard Green started Tuesday as the new president and chief executive officer of the Queen’s Health Systems, succeeding longtime CEO Art Ushijima who will serve as adviser until Jan. 31.

Queen’s in May announced the selection of Hoggard Green, a 39-year health care veteran and registered nurse.

The administrative change comes during a tumultuous time.

Queen’s is being sued by Kaiser Permanente in federal court for “unfair billing practices” after the hospital said it would directly bill Kaiser members who receive emergency medical services at its facilities after a hospital services agreement expired on May 30.

The hospital is also facing scrutiny from some physicians after replacing a dozen local doctors with Envision Healthcare Corp., one of the nation’s largest physician­-staffing companies, to take care of surgical patients as of Sept. 1. Envision, based in Nashville, Tenn., has come under fire nationally for allegedly charging insurers and patients higher rates than warranted and for not participating with certain health insurance.

“Over the coming weeks, I look forward to spending time listening and talking with people across the organization and the state,” Hoggard Green said in a statement. “It is critical that we work together to address the needs of our communities and fulfill the Queen’s mission of providing quality health care to all of the people of Hawaii.”

Hoggard Green previously was the president of Mission Hospital in Asheville, N.C., and was the former chief operating officer of its parent company, Mission Health, a $2 billion health system. Ushijima will be the adviser to the CEO to ensure a smooth transition until his retirement in January.