Bertolini has served on the CVS board since November 2018, when CVS purchased Aetna for $69 billion. CVS said in a statement Monday that he would not stand for reelection after the company's annual meeting and that it was reducing the size of the board from 16 to 13.
Bertolini said he was willing to remain on the board and that the integration between CVS and Aetna "is far from over," according to the Journal.
CVS had a different take on the matter: "With the bulk of the integration behind us and the Aetna business performing strongly, the board felt it was the right time for Mark to focus on his other endeavors," said T.J. Crawford, vice president of external Affairs for CVS Health, in a statement to CNBC.
CVS Chairman David Dorman thanked Bertolini "for his contribution to the successful integration of Aetna" in the statement announcing the changes. Richard Swift and Richard Bracken will also depart the board after the company's annual meeting.