The day to day operations of the medical center are carried out under the leadership of our administrative team.
Brian Dieter, FACHE, President/Chief Executive Officer
email: Brian Dieter
Brian Dieter has served as president and CEO of Mary Greeley Medical Center since July 2008. Prior to that, he was the medical center’s chief financial officer for nearly nine years.
Before joining Mary Greeley, he spent 10 years at Ancilla Systems Inc. at three affiliated healthcare organizations in financial leadership positions. He received his Bachelor of Science degree in Business from Indiana University in 1985 and his Master of Science degree in Administration from the University of Notre Dame in 1998. He is a Fellow in the American College of Healthcare Executives and former board chair for the Iowa Hospital Education and Research Foundation (IHERF). Dieter is the treasurer of the Iowa Hospital Association. He also serves on the Iowa Healthcare Collaborative and Health Enterprises boards. He is active in a variety of community organizations, including the Ames Chamber of Commerce, Ames Economic Development Commission, Rotary Club of Ames, and United Way of Story County.
Cory Geffre, BSN, MS, Vice President/Chief Nursing Officer
email: Cory Geffre
Cory Geffre, BSN, MS, has served as Vice President and Chief Nursing Officer of the Medical Center since January 2019. Prior to this he was Vice President and Chief Nursing at Avera St. Luke’s Hospital in Aberdeen, S.D, from 2016 to 2019. His previous positions include Cardio-Renal Services Nurse Manager at Avera St. Luke’s Hospital and sales representative and business growth specialist with Zimmer Biomet, a medical device manufacturer. He also operated his own consulting firm, which helped businesses with strategy, market innovation, growth and leadership development. As vice president and CNO at Mary Greeley, Geffre oversees the medical center’s inpatient and outpatient nursing services, including Cancer Services, Cardiology Services, Behavioral Health, Birthways, Emergency Department, Pharmacy, and Home Health and Hospice. He has an Associate Degree in Nursing from the University of South Dakota, Vermillion, a Bachelor of Science in Nursing from the University of Texas at Arlington, and a Master of Science in Management, Strategy and Leadership from the Eli Broad College of Business at Michigan State University in East Lansing.
Amber Deardorff, BSN, RN, MPA, Vice President/Clinical and Support Services
email: Amber Deardorff
Amber Deardorff has served as a Vice President of the Medical Center since May 2017. Prior to this, she had several positions at Mary Greeley, including Director of Clinical Application Systems from 2012 to 2017; Clinical Applications Manager from 2009 to 2012; Clinical Information Coordinator from 2006 to 2012; and Registered Nurse in Intensive Cardiac Care Unit from 2004 to 2006. A long time Ames resident and Ames High School graduate, Deardorff obtained her Bachelor of Science degree in Exercise and Sports Science from Iowa State University in 2002. She received a Bachelor of Science degree in Nursing from Grand View College in 2004. In 2012, Deardorff obtained her Master of Public Administration degree from Drake University. She is a 2016 Iowa Hospital Association Hospital Executive Academy graduate, as well as an Iowa Hospital Association Health Care Leadership Series graduate. She has been active in a variety of community organizations in Ames and Story County, including Friendship Ark Homes, the United Way of Story County, and the Ames Community Preschool Center.
Karen Kiel Rosser, Vice President/Quality Improvement Officer
email: Karen Kiel Rosser
Karen Kiel Rosser serves as the Vice President & Quality Improvement Officer for Mary Greeley Medical Center. Before joining Mary Greeley Medical Center, she was the Vice President of Performance Excellence and Managed Care at Agnesian HealthCare, an integrated health care delivery system in Fond du Lac, WI. In this role, Kiel Rosser spearheaded the development and implementation of a system-wide framework for performance excellence utilizing criteria from the Malcolm Baldrige National Quality Award Program as well as the tools of lean and six sigma. Her positions prior to Agnesian HealthCare included Network Development Director at Humana Health Plan in Milwaukee, WI, and Ambulatory Clinic Manager for Aurora Health Care in Milwaukee, WI. She holds a Master’s Degree in Health Care Administration from the University of Minnesota and a Bachelor’s degree in Communications and Public Relations from the University of Wisconsin, Whitewater. Kiel Rosser is a certified lean six sigma green belt, an examiner, coach and judge for the Iowa Recognition for Performance Excellence Program, and is on the Board of Examiners for the Baldrige National Quality Award Program. Additionally, she is a member of the Ames Morning Rotary Club, a board member for United Way of Story County, and a participant in Leadership Ames (class XXIV) program.
Gary Botine, Vice President/Chief Financial Officer
email: Gary Botine
Gary Botine joined the Medical Center in March 2014 as Vice President/Chief Financial Officer. Prior to that, Botine served as vice president for human resources at Danfoss Power Solutions. In that position he was responsible for human resources functions for an organization of 6,500 employees. Botine joined Sauer-Danfoss (now Danfoss Power Solutions) in 1993 and served in a number of leadership positions with the global manufacturing company in the areas of human resources, finance, manufacturing, and information technology. Botine began his career in public accounting with Deloitte & Touche and Grant Thornton. He is a certified public accountant. He received his Bachelor of Arts degree in Accounting from University of Northern Iowa in 1986. Botine has been active in a variety of community organizations in Ames and Story County, including chairing the 2011 United Way of Story County campaign, serving on the Ames Public Library Board of Directors, Ames Noon Rotary Club Board of Directors, the Center for Creative Justice Board of Directors, President of the Bethesda Lutheran Church Council, an examiner for the Iowa Recognition for Performance Excellence Program, and the Ames Chamber of Commerce Board of Directors. Botine and his wife, Heather, also spearheaded a $300,000 capital campaign for the Ames Community School District. Botine currently serves on the Board of Directors of the Ames Convention and Visitors Bureau, chairs the Main Street Cultural District (MSCD) economic development committee and serves on the MSCD Board of Directors.
Board of Trustees
As a city-owned hospital, Mary Greeley Medical Center is governed by a board of five elected medical center trustees. The day-to-day operations of the medical center are carried out under the leadership of our administrative team.
Sarah Buck, Chair
email: Sarah Buck
Term Expires: 2023
Ken McCuskey, Secretary/Treasurer
email: Ken McCuskey
Term Expires: 2023
email: Austin Woodin
Term Expires: 2023
email: Mary Kitchell
Term Expires: 2025
email: Beth Swenson
Term Expires: 2025
Medical Staff Leadership
The administrative oversight of our providers is carried out by our medical staff leadership group.
Bonnie Beer, MD
Chief of Staff
Shane Hopkins, MD
Chief of Staff Elect
Jotesh Chug, MD