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Our Leaders

Our executive leadership strives to continually achieve our aim of providing better health care - and a better health care system - to every patient we serve.

Hal Teitelbaum
Hal Teitelbaum MD, JD, MBA

Managing Partner & CEO

Dr. Hal Teitelbaum is the Founder, Managing Partner and Chief Executive Officer of Crystal Run Healthcare—a premier multi-specialty group medical practice. Dr. Teitelbaum completed his training in Internal Medicine at New York Hospital-Cornell Medical Center, and in Medical Oncology and Hematology at Memorial Sloan-Kettering Cancer Center. After beginning his career in full-time academic practice, Dr. Teitelbaum established a solo practice in Orange County, New York, in 1982. He established Crystal Run Healthcare in 1996. Dr. Teitelbaum is a 1998 Honors graduate of Columbia Business School, where he earned his MBA. He earned his Juris Doctor degree from Columbia Law School, Class of 2012, where he was a Harlan Fiske Stone Scholar.

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Michelle A. Koury MD

Chief Operating Officer

Dr. Michelle A. Koury is the Chief Operating Officer at Crystal Run Healthcare. Dr. Koury is a cum laude graduate of Rutgers University and attended medical school at Tufts University School of Medicine. She completed her residency in Internal Medicine at New England Medical Center-Tufts University School of Medicine, Boston, MA. A board certified Internist, Dr. Koury joined Crystal Run Healthcare in 1996, after which she earned her certification as a medical director for long-term care – one of only two in Orange County at the time. Dr. Koury was appointed as Crystal Run Healthcare’s first Medical Director in 2002 and served in that role for six years, until being appointed Chief Operating Officer in 2008.

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Gregory A. Spencer MD, FACP

Chief Medical Officer & Chief Medical Information Officer

Dr. Gregory A. Spencer is the Chief Medical Officer and Chief Medical Information Officer at Crystal Run Healthcare. Dr. Spencer graduated from the Medical College of Wisconsin (Marquette University) Medical School and completed his residency in Internal Medicine while in the US Air Force at Wilford Hall USAF Medical Center in San Antonio, TX. Dr. Spencer joined Crystal Run as an internist in 1996 and was appointed as Chief Medical Officer and Chief Clinical Information Officer in 2008. Dr. Spencer is board certified in Internal Medicine and is a Fellow of the American College of Physicians.

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Mary DeFreitas BBA, MPS

Chief Human Resources Officer

Mary DeFreitas is the Chief Human Resources Officer at Crystal Run Healthcare. Ms. DeFreitas is a graduate of Pace University in Pleasantville, NY, where she earned her Bachelor of Business Administration in Marketing. Ms. DeFreitas holds her Masters of Professional Studies in Humanistic Education from SUNY New Paltz. Ms. DeFreitas is also a graduate of Leadership Orange, class of 2002.

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Gaynor Rosenstein MS, CMPE

Chief Clinical Operations Officer

Gaynor Rosenstein is the Chief Clinical Operations Officer at Crystal Run Healthcare, a position she has held since 2008. Ms. Rosenstein holds a Bachelor of Arts from Crewe and Alsager College in Crewe, UK, and her General Nursing (RN) degree from Blackburn School of Nursing, Blackburn, UK. Ms. Rosenstein earned her Master of Science in Healthcare Administration from New School University in New York, NY and is a Licensed Nursing Home Administrator by the State of New York. In addition, Ms. Rosenstein is a Certified Six Sigma Black Belt and Certified Medical Practice Executive as well as a graduate of Leadership Orange, class of 2011.

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Douglas Sansted JD

Chief Legal Officer

Douglas Sansted is the Chief Legal Officer at Crystal Run Healthcare. Mr. Sansted holds a Bachelor of Science degree in Nursing from the City University of New York Hunter College where he was a summa cum laude graduate and class valedictorian. Mr. Sansted earned his Juris Doctor degree from New York University School of Law in New York, NY. Mr. Sansted is a member of the New York State Bar Association and is a member of the American Health Lawyers Association.

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Erlene Washington MS

Senior Vice President of Finance & Accounting

Erlene Washington is the Senior Vice President of Finance and Accounting at Crystal Run Healthcare. Ms. Washington is a graduate of Wellesley College in Wellesley, MA, where she earned her Bachelor of Arts. Washington also holds a Master of Science in Accountancy from Bentley College in Waltham, MA. In addition, Washington is a graduate of the Emerging Leaders Program at the Center for Collaborative Leadership College of Management at the University of Massachusetts in Boston, MA.

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Christine K. Wise-Vazquez LNHA, CMPE

Senior Vice President of Support Services

Christine K. Wise-Vazquez is the Senior Vice President of Support Services at Crystal Run Healthcare. Wise-Vazquez is a cum laude graduate from Mount Saint Mary College in Newburgh, NY, where she received her Bachelor’s Degree and is now completing her Master’s in Business Administration. In addition, Ms. Wise-Vazquez is a New York State Licensed Nursing Home Administrator and a Certified Medical Practice Executive.

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Scott Hines MD

Chief Quality Officer, Medical Director

Scott Hines, MD, is Crystal Run Healthcare’s Chief Quality Officer, Medical Director, and physician leader for Crystal Run Healthcare’s medical specialties division. Dr. Hines is board certified in Internal Medicine, Endocrinology, Diabetes and Metabolism. Dr. Hines earned his Medical Degree from the Wake Forest University in Winston-Salem, NC, and completed his residency in Internal Medicine at the Dartmouth-Hitchcock Medical Center in Lebanon, NH. Dr. Hines completed his Endocrinology Fellowship at the University of Maryland Medical Center in Baltimore, MD. In 2006, Dr. Hines joined Crystal Run Healthcare. 

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Jonathan Nasser MD

Chief Clinical Transformation Officer, Medical Director

Jonathan Nasser, MD is Crystal Run Healthcare’s Chief Clinical Transformation Officer, Medical Director, and physician leader for Crystal Run Healthcare’s Pediatrics division. Dr. Nasser is board certified in Pediatrics and Internal Medicine. Dr. Nasser earned his Medical Degree from the University of Virginia in Charlottesville, VA, and completed his residency at the University of Rochester Medical Center in Rochester, NY. In 2002, Dr. Nasser joined Crystal Run Healthcare. As Chief Clinical Transformation Officer, Dr. Nasser is responsible for instituting programs that advance Crystal Run’s transition to value based care. 

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Francis H. Cheung - Chief Information Officer
Francis H. Cheung

Chief Information Officer

Francis H. Cheung is the Chief Information Officer at Crystal Run Healthcare. Mr. Cheung is a graduate of University of Wisconsin, Madison in Madison, Wisconsin where he earned his Bachelor and Master of Science in Industrial Engineering. Mr. Cheung is Lean Production Certified and his professional affiliations include membership to the College of Healthcare Information Management Executives (CHIME) and the Healthcare Information and Management Systems Society (HIMSS).

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