The Centene board accepted the resignation of Leslie Norwalk April 15.
In an April 11 letter to the board, Ms. Norwalk said the process surrounding a recent important decision fell egregiously short of what she and other board members considered appropriate to make an informed decision. She said the full board did not receive adequate information and did not have any opportunity for discussion and debate ahead of the vote.
The decision was not specified in the letter.
The board said it appreciated Ms. Norwalk's contribution to her company and her service, according to a company news release.
Ms. Norwalk was appointed to the board in January. She previously served on the board of Magellan Health, which Centene acquired Jan. 4.