Thursday, June 25, 2020
Greenwich, CT (June 25, 2020) – Greenwich Hospital announced today that Diane P. Kelly, DNP, RN has been appointed Greenwich Hospital’s new president effective immediately. The appointment of Kelly follows the decision by Greenwich Hospital President and CEO Norman Roth to retire this Fall. The Hospital also announced that Marc Kosak has been appointed as the new chief operating officer, following Kelly’s promotion to the role of president. Kosak’s appointment will be effective on October 3.
“Diane Kelly has been an extremely effective leader throughout her career,” said Roth. “Since joining Greenwich Hospital in 2018, she has made a clear and a positive impact on the entire hospital community. Most recently, Diane has demonstrated exceptional talent in guiding the hospital through an historic pandemic. I am confident that she brings the right commitment and expertise to successfully lead Greenwich Hospital well into the future.”
Kelly has served as Greenwich Hospital’s chief operating officer since 2018. She began her career at the Berkshire Medical Center, serving in a variety of frontline nursing roles, also serving as clinical leader of the Psychiatric Unit and as vice president of Quality & Safety. She went on to serve as the chief operating officer of BMC from 2008 until she accepted the position at Greenwich Hospital a decade later.
“In Diane Kelly, we have a proven leader,” said Arthur Martinez, chair of the Greenwich Hospital Board of Directors. “In the two years that Diane has served as the COO, she has demonstrated strong strategic and implementation skills. She is well respected at the hospital and in the community. The Board looks forward to working with Diane in her new role as president of Greenwich Hospital.”
Kelly received her Doctorate in Nurse Practice from the University of San Francisco with an emphasis on executive leadership practice and population health. A graduate of Western New England College with a Master's degree in Business Administration, she earned her BS in Nursing from the University of Massachusetts at Amherst. She is a member of the American College of Healthcare Executives, she also holds a certification as Nurse Executive and is a member of Sigma Theta Tau International. Sigma Theta Tau membership is by invitation only to those who demonstrate excellence in scholarship and exceptional achievements in nursing.
“Diane has a proven track record in health care administration with many years of experience in direct patient care as well as in hospital operations,” said Marna P. Borgstrom, CEO of Yale New Haven Health. “She has become an intrinsic part of Yale New Haven Health and is the perfect choice to lead Greenwich Hospital out of the pandemic and into clinical growth.”
Marc Kosak has worked at Greenwich Hospital since 2004. Prior to his new appointment as chief operating officer, Kosak served as senior vice president of Operations at Greenwich Hospital since 2015. Kosak has also served as the vice president of Administration and prior to that the administrative director of Physical Medicine.
“Marc brings a wealth of experience to his new role as chief operating officer,” said Diane P. Kelly. “He is well known and exceptionally well respected here in Greenwich and across Yale New Haven Health. We are privileged to have someone with his talent on our team and I look forward to working with him as we collectively take on new challenges."
Prior to joining Greenwich Hospital, Kosak spent 10 years working for Burke Rehabilitation Hospital in a variety of positions with increasing responsibility. Marc is a Fellow of the American College of Healthcare Executives.
5/14/2026
Greenwich Hospital earns five-star rating by CMSGREENWICH, CT (May 14, 2026) – Greenwich Hospital has earned a prestigious five-star overall hospital quality rating from the Centers for Medicare & Medicaid Services (CMS), recognizing the hospital for outstanding performance in patient safety, clinical quality and the exceptional experience it provides to patients and families.
5/12/2026
Greenwich Hospital celebrates Nurses’ Day by honoring excellence in nursing, collaboration and partnership in careGREENWICH, CT (May 12, 2025) – Greenwich Hospital celebrated its annual Nurses’ Day Celebration on Monday, May 11, recognizing staff members, physicians and nurses who exemplify compassion, collaboration and a deep commitment to patient-centered care. All honorees were nominated by and voted on by hospital employees.
5/6/2026
Yale New Haven Health Hospitals Earn “A” Hospital Safety Grades from The Leapfrog GroupNEW HAVEN, CT (May 6, 2026) – Bridgeport Hospital, Greenwich Hospital, Yale New Haven Hospital and Westerly Hospital (RI) earned an “A” Hospital Safety Grade from The Leapfrog Group, a national nonprofit watchdog focused on patient safety, underscoring Yale New Haven Health’s ongoing commitment to delivering the safest possible care.