RN Quality Review & Performance Improvement Oceanside, NY. Situated on the sunny south shore of western Long Island, minutes from Jones Beach and thirty minutes from NYC, is an exceptional Magnet® Hospital focused on quality and excellence . . . Mount Sinai South Nassau.  Named a Best Regional Hospital, by U.S. News & World Report, Mount Sinai South Nassau is one of the region’s largest award-winning hospitals, with 455 beds, more than 900 physicians and 3,500 employees. The hospital is an acute-care, not-for-profit teaching hospital affiliated with the world-class Mount Sinai Health System and Icahn School of Medicine that provides state-of-the-art care in cardiac, oncologic, orthopedic, bariatric, pain management, mental health and eme