(Reuters) - Anthem Inc's ANTM.N Joseph Swedish will be replaced as chief executive by industry veteran Gail Boudreaux but will stay on as executive chairman until May 2018 and be a senior adviser through May 2020, the health insurer said on Monday.

People enter the office building of health insurer Anthem in Los Angeles, California February 5, 2015. REUTERS/Gus Ruelas

The Wall Street Journal first reported the news on Friday.

Swedish will continue to receive his current salary as executive chairman and be eligible for a prorated bonus and as an adviser, he will be paid $4.5 million per year.

Swedish's move comes at a time of change for Anthem, the No. 2 U.S. health insurer. The company cut Obamacare individual market participation by 70 percent for next year and recently announced plans to bring its pharmacy benefit management in house. It also may face a much larger Aetna Inc AET.N, which is considering a deal with CVS Health Corp CVS.N, according to sources.

Boudreaux was most recently CEO of United Healthcare, a unit of the biggest U.S. health insurer, UnitedHealth Group Inc UNH.N. Before that, she was an executive at the next largest operator of Blue Cross Blue Shield licensed insurers, Health Care Services Corp, and at Aetna.

BMO Markets analyst Matthew Borsch said in a research note that Boudreaux is held in high regard by investors but that Anthem’s stock is still a “market-perform” given the company’s slower-growth business mix.

“We expect there may be a period of uncertainty among investors until the reasons for the reported leadership change are understood and fully accepted by the market,” he wrote.

Boudreaux, who will take on the role of CEO on Nov. 20, will receive an annual salary of $1.4 million with a potential bonus of up to 350 percent of her salary, along with an initial stock grant worth $2 million. Long-term incentives are worth up to $10.25 million.

Swedish orchestrated Anthem's $54 billion deal for smaller rival Cigna Corp CI.N in 2015, which was ultimately scrapped as regulators said that and Aetna's proposed acquisition of Humana Inc HUM.N would be anti-competitive.

Two weeks ago, news broke that Aetna and CVS were in talks over a deal that would create a combined health insurance, pharmacy benefit management, and pharmacy company. The deal is expected in December, Reuters reported.

The impact of that deal is unclear on Anthem's recently announced plan to use CVS to help manage its pharmacy benefits business as it exits its contract with Express Scripts Holding ESRX.O.