UnitedHealth Group (NYSE: UNH) announced on Tuesday that CEO Andrew Witty has stepped down from his role. The company has named board Chairman Stephen Hemsley as his replacement.

The appointment is effective immediately. Witty made the decision to step away for “personal reasons,” according to a UnitedHealth Group press statement.

“We are grateful for Andrew’s stewardship of UnitedHealth Group, especially during some of the most challenging times any company has ever faced,” Hemsley said in the press statement. “The board and I have greatly valued his leadership and compassion as chief executive and as a director and wish him and his family the best.”

Witty, who has held the CEO role at UnitedHealth Group since 2021, will serve as a senior adviser to Hemsley. Prior to joining UnitedHealth Group, he was the CEO of pharmaceutical company GlaxoSmithKline.

In addition to his new responsibilities, Hemsley will remain in his role as chairman. He previously held the UnitedHealth Group CEO position from 2006 to 2017.

Aside from the CEO announcement, UnitedHealth Group also suspended its 2025 forecast.

On a UnitedHealth Group transition call on Tuesday, Hemsley apologized for the performance difficulties that the company has faced over the years.

“I’m deeply disappointed in, and apologize for, the performance setbacks we have encountered with both external and internal challenges,” he said during the call. “Many of the issues standing in the way of achieving our goals, as well as our opportunities, are largely within our control. I am optimistic about our future, as these issues are within our capacity to resolve, we will approach them with humility, rigor and urgency.”

Looking ahead, Hemsley expressed his belief that the company is well-positioned to lean into growth opportunities.

“UnitedHealth Group has tremendous opportunities to grow as we continue to help improve health care and to perform to our potential — and, in so doing, return to our long-term growth objective of 13% to 16%,” he said in the press statement.

The company has previously set a goal of 13% to 16% earnings per share.

It has been an eventful, and at times tumultuous, few years for UnitedHealth Group.

Last December, the CEO of UnitedHealthcare, UnitedHealth Group’s health benefits business, was killed in New York City, while attending the company’s annual investor conference.

Early last year, Change Healthcare – the largest U.S. billing and payment system in the country, and a subsidiary of UnitedHealth Group, experienced a major cyberattack. The cybersecurity breach caused waves across the health care industry.

In February, reports surfaced that the U.S. Department of Justice (DOJ) was pursuing a civil fraud investigation regarding UnitedHealth Group’s Medicare Advantage billing.

Amid all of this, UnitedHealth Group’s attempted $3.3 billion purchase of home-based care giant Amedisys Inc. (NASDAQ: AMED), which began in 2023, has faced several roadblocks. Last November, the DOJ sued to stop the deal. The DOJ claimed that the transaction was “anticompetitive.”

In response, Amedisys made plans to divest over 100 home health and hospice locations to VitalCaring. However, the deal was blocked when a federal court ruled that VitalCaring was required to set aside a large portion of its future earnings to Encompass Health and Enhabit.

In May, Amedisys cemented a deal to offload home health and hospice locations to the Pennant Group (Nasdaq: PNTG) and BrightSpring Health Services (Nasdaq: BTSG). This week, it was revealed that the DOJ has, reportedly, rejected this plan. 

The DOJ, Amedisys and UnitedHealth Group will begin mediation on August 18.