MidMichigan Health Senior Leadership

Diane Postler-Slattery, Ph.D.
President and Chief Executive Officer, MidMichigan Health

Diane became MidMichigan Health president and chief executive officer on January 14, 2013, which brought her to Michigan. Prior to that, she was president & chief operating officer of Aspirus Wausau Hospital and Senior Vice President of Quality and Extended Services for the Aspirus system. 

Diane holds a Ph.D. in education administration from the University of Wisconsin – Madison as well as a Master of Science in nursing/nursing administration and Bachelor of Science in nursing from the University of Wisconsin – Eau Claire. 

Diane is active in many professional and civic organizations. She is a Fellow of the American College of Healthcare Executives. Diane is a board member of the Midland Center for the Arts, The Midland Business Alliance, Michigan Baseball Foundation, Michigan Health & Hospital Association, Affirmant Health Partners, Alma College, and THRIVE (Transforming Healthcare Regionally In a Vibrant Economy). She is a member of the Midland 100 Club and the Midland Business Alliance Innovation Center Advisory Committee. She is lead director of IncredibleBank’s  board of directors. Diane is the chair of the American Hospital Association’s 2019 Go Red for Women campaign.

Diane has received numerous awards, which include a Woman of Vision, Athena, University of Wisconsin-Eau Claire President’s Award, State of Wisconsin Nurse Leader of the Year, State of Wisconsin Champion in Women’s Health, Great Lakes Bay YWCA Woman of Achievement, and Junior Achievement Business Hall of Fame Laureate

Greg Rogers
Executive Vice President and Chief Operating Officer, MidMichigan Health

Greg is a certified public accountant and a fellow in the Healthcare Financial Management Association with certifications in healthcare finance, managed care and patient accounting. He received his Bachelor of Arts degree from Albion College and completed additional Masters of Business Administration courses at Central Michigan University. Greg has held local, state and national positions in many professional organizations and has been active in community service and sports organizations.

Prior to his current position, Greg served as senior vice president & treasurer of MidMichigan Health and MidMichigan Medical Center – Midland. Prior to that, he served as vice president and controller for Midland. He joined MidMichigan in 1981.

Dua'a Weber (Dee)
Senior Vice President and Chief Human Resources Officer, MidMichigan Health

Dee is senior vice president of Human Resources for MidMichigan Health. Her responsibilities include Strategic oversight and implementation of all Human Resources areas including: Talent Acquisition, Workforce Development, Labor Affairs, Employee Engagement, Staff and Leadership Learning and Development, Total Rewards, Human Resources Information Systems, and Employee Health and Wellness. Dee is active on several boards and has oversight responsibility for the Compensation Committee at MidMichigan Health.

Prior to joining MidMichigan Health ,Dee was responsible for Human Resources at Southwest General Health System in Middleburg Heights, Ohio. Dee and her team attained the Employer of Choice status and were the only health care system in Ohio to gain this designation. Dee has been in Human Resources for the past 30 years and has worked in publicly traded as well as privately held and nonprofit health care organizations. Dee earned her Bachelor as well as Master degrees from the University of Toledo. Dee is fluent in Arabic and enjoys her new hometown, Midland.

Mike Rose
Senior Vice President and Chief Financial Officer, MidMichigan Health

Mike joined MidMichigan Health in October 2020. He has nearly 30 years of healthcare experience and has served as CEO for a single hospital system and CFO for a regional system. Mike has experience working with academic medical centers, large physician practice groups, and has created unique partnerships with commercial insurance companies. Mike completed his undergraduate degree in Accounting from Longwood University, received his master's in Business Administration from Virginia Commonwealth University and is a Certified Public Accountant. 

Mike grew up in Virginia and has made stops along his career journey in New Jersey and New Hampshire. He is married with three adult children and enjoys outdoor activities such as skiing, hiking and mountain biking.  

Lydia Watson, M.D., C.P.E.
Senior Vice President and Chief Medical Officer, MidMichigan Health

Lydia was appointed to her current position effective July 8, 2013. Prior to this, she had served as Chair of the Obstetrics/Gynecology Department, Chief of Staff, and Vice President of Medical Affairs for MidMichigan Medical Center – Midland.

Lydia has been a member of MidMichigan’s medical staff since 1996. She received her Medical Degree from Wayne State University School of Medicine, Detroit, and completed a residency in obstetrics and gynecology from Saginaw Cooperatives Hospitals, Saginaw. She is a Fellow of the American College of Obstetrics and Gynecology and member of the Alpha Omega Alpha Medical Honor Society, Michigan State Medical Society and Midland County Medical Society. Lydia is a board member of the Strosacker Foundation and the Shelterhouse of Midland and Gladwin counties. In 2017, she received the Athena Award. Lydia holds a Certified Physician Executive (CPE) certificate in medical management.

Paul Berg, M.D.
President, MidMichigan Physicians Group

Paul was named President of MidMichigan Physicians Group in February 2018. He is a Board Certified Family Physician and has been employed by MidMichigan Physicians Group since 2008.

Paul received his Medical Degree from Michigan State University College of Human Medicine in East Lansing, and completed his family practice residency at MidMichigan Medical Center – Midland. He holds a Master of Science in Healthcare Administration and Leadership from Saginaw Valley State University. Paul is a member of the American Academy of Family Physicians, the American College of Healthcare Executives, and the Midland County Medical Society.

Mary Greeley, M.S., R.D.
President, MidMichigan Health Network

In 2015 Mary was appointed President of MidMichigan Health Network, a joint venture between Physician Associates of MidMichigan, P.C. and MidMichigan Health. In her role, she oversees payor contracting and ConnectCare, a self-funded insurance plan. Additionally, she coordinates population health efforts in our communities.

Mary's background is in dietetics and diabetes management. She holds a Master of Science degree in Nutrition from Michigan State University and received her Bachelor of Science degree in Biology and Chemistry from Calvin College.

Mary serves on the Board of Directors of the Michigan Health Improvement Alliance (MiHIA) and Senior Services of Midland County.

Bryan Cross
President, MidMichigan Medical Center – Midland

Bryan Cross, Pharm.D., was appointed president of MidMichigan Medical Center – Midland in March 2021. With more than 30 years of experience in health care, Bryan began his career with MidMichigan as a paramedic supervisor. After earning a Doctor of Pharmacy degree, he transitioned to the manager of pharmacy, then spent 13 years as the corporate director of pharmacy, receiving the prestigious MidMichigan Health Chairman’s Award in 2006. In his previous position as the health system vice president of professional services, Bryan was instrumental in the strategic planning and coordinating of the COVID-19 response initiatives and vaccination program. He also holds a master’s degree in business administration. Bryan is married with four children, three of whom are, or will soon be, working in the field of health care.

Marita Hattem-Schiffman
Regional President, MidMichigan Health

In January of 2020, Marita was named Regional President of MidMichigan Health with areas of responsibility including MidMichigan Medical Center – Clare, MidMichigan Medical Center – Gratiot and MidMichigan Medical Center – Mt. Pleasant. In July of 2017, she was named the President of MidMichigan Medical Center's in Gratiot and Mt. Pleasant. 

A native of Spring Lake, Mich., Marita holds a master’s degree in business administration from the University of St. Francis in Ft. Wayne, Ind., and a bachelor’s degree in psychology with honors from Central Michigan University in Mt. Pleasant.

She joined MidMichigan Health from Wausau, Wis., where she had a wide range of responsibilities. Marita served as the chief experience officer of Connexus Credit Union for two and a half years before joining MidMichigan Health. Prior to that she was with the Aspirus health system, also in Wausau, where she held positions of increasing scope and responsibility from vice president of physician support services to interim president and chief operating officer of the Aspirus Wausau Hospital and finally senior vice president of provider relations and service lines for Aspirus, Inc.

Marita is a Fellow of the American College of Health Care Executives, and also holds a Certification in Professional Medical Services Management. In addition, she is a registered yoga teacher.

Marita believes strongly in community service and has been active with organizations such as the United Way and the YWCA.

Chuck Sherwin
Regional President, MidMichigan Health

Chuck was named President of MidMichigan Medical Center – Alpena in July 2018. He came to Alpena General Hospital as the Director of Organizational Improvement in 1996 and was named Administrator of the Alpena Cancer Center in 1999. In 2008, Chuck was named Vice President of Business Development and Clinical Services and in 2014 added Chief Nursing Officer to his role. Chuck is a Fellow of the College of Healthcare Executives (ACHE) and was certified as a Professional in Healthcare Quality (CPHQ).

Chuck holds a Bachelor of Science in Nursing from Olivet Nazarene University and a Master of Science in Health Care Administration from the University of Detroit. He is Vice President of the Board of Directors for Alcona Citizens for Health, President of the Rotary Club of Alpena, and President of the Board for Northeast Michigan Cancer Center.

Ray Stover
Regional President, MidMichigan Health

Ray was named Regional President of MidMichigan Health in January of 2020. His areas of responsibilities include MidMichigan Medical Center – Gladwin and MidMichigan Medical Center West Branch. Ray served as the President of MidMichigan Medical Center – Clare and MidMichigan Medical Center – Gladwin from 2009-2019 after serving as the Vice President and Chief Financial Officer at MidMichigan Medical Center – Clare from 2005 to 2008. He has been employed with MidMichigan Health since 1990 where he has held the positions of management analyst, cost/budget manager and accountant.

Ray holds a Master of Science degree in Health Administration and Leadership from Saginaw Valley State University and a Bachelor of Science in Business Administration with a major in accounting from Saginaw Valley State University.

Ray serves on the Board of Directors for the Mid Michigan College Foundation, MidMichigan Community Health Services, the Gladwin County Economic Development Committee, and the Central Michigan University Master of Public Health Advisory Board. He is a member of the Gladwin Rotary Club, the West Branch Optimist Club, and the Beaverton and Harrison Lions Club.

Dan Waltz
Vice President and Chief Information Officer, MidMichigan Health

Dan is Vice President and Chief Information Officer of MidMichigan Health. He has extensive health care administrative and information technology experience. He joined MidMichigan Health in January 2014 after 13 years at Michigan Medicine where he was an Executive Director of hospital information technology and Program Director for the electronic medical record transformation. Prior to Michigan Medicine, Dan was the Chief Information Officer of Chelsea Community Hospital.

Dan earned his Master of Business Administration from the University of Phoenix and a Bachelor of Science degree in Organizational Development from Eastern Michigan University.