Dixon had served as Community's chief operating officer since 2003.
Community spokeswoman Lynda de Widt said Dixon is not replacing another executive, but she would not elaborate.
The Community system includes campuses on east, north and south sides of Indianapolis as well as Community Home Health Services. The network has more than 70 sites of care throughout central Indiana.
"This is a natural progression for Mark and the network," Bill Corley, president and CEO of Community Health Network, said in a release. "Mark will assume greater responsibility and work directly with the Community Hospitals of Indiana board as CHI continues to grow."
Dixon earned pharmacy and master of health administration degrees from the University of Minnesota. He joined Community Hospitals with more than 20 years of leadership in the health care industry.