Sharon Poston has left her role as CEO of Williamsburg Regional Hospital in Kingstree, S.C., reports kingstreenews.com.

The following hospital and health system chief nursing officer, chief nursing executive and chief medical officer moves were reported in the last four weeks.   

Robert Marmerstein has been tapped to serve as CEO of HCA Houston Healthcare Tomball (Texas), effective July 13. 

The following women leadership moves have been reported since June 11:

The following hospital and health system executive moves were reported in the last week: 

Roland Bibeau, RN, president and COO of Novant Health Matthews (N.C.) Medical Center, is retiring, effective June 30, the hospital confirmed.

Dallas-based Tenet Healthcare has named Sheri Montgomery CEO of Good Samaritan Medical Center in West Palm Beach, Fla., reports southfloridahospitalnews.com.

Sioux Falls, S.D.-based Avera Health has named Ashli Danilko CEO of St. Michael's Hospital Avera in Tyndall, S.D., effective Sept. 12, yankton.net reports. 

Peoria, Ill.-based OSF HealthCare has named Kathleen Kinsella president of Little Company of Mary Medical Center in Evergreen Park, Ill., effective July 10.

John Krahnert Jr., MD, and Lynn DeJaco are stepping down from their executive roles at FirstHealth of the Carolinas in Pinehurst, N.C., the health system confirmed.

Pittsburgh-based Allegheny Health Network has named Chong Park, MD, president of Jefferson Hospital in Jefferson Hills, Pa., and Canonsburg (Pa.) Hospital.

Kris Zimmer will retire from St. Louis-based SSM Health, effective July 13, the health system announced.

The following hospital and health system CEO moves have been reported since June 15. 

Cleveland Clinic Florida CEO Wael Barsoum, MD, is resigning to take a new leadership job at a private company, the Sun Sentinel reports.

Ypsilanti, Mich.-based Saint Joseph Mercy Health System named Alonzo Lewis president of St. Joseph Mercy Ann Arbor (Mich.) and St. Joseph Mercy Livingston in Howell, Mich.

Cleveland Clinic has named Kelly Hancock, DNP, RN, as its first chief caregiver officer. 

Jan Keys, DNP, RN, senior vice president and chief nursing executive of Chattanooga, Tenn.-based Erlanger Health System, retired June 22, according to an internal memo to staff from CEO Will Jackson, MD.

Renton, Wash.-based Providence health system has tapped A. Verona Dorch to serve as executive vice president and chief legal officer.

The following hospital and health system executive retirements were reported from January through June 22.

Los Angeles-based Keck Medicine of USC tapped Chris Allen to serve as interim CFO, effective June 19, according to a memo to staff provided to Becker's Hospital Review.