Gramercy Pediatrics was founded in 2010 and has been serving children and adolescents in the downtown New York City area for the past 13 years. Our physicians are excited to join Northwell Health and to continue to provide the highest level of primary care for our patients in Manhattan. We are looking forward to being part of a new network of pediatric specialty providers and to seeing babies in the Lenox Hill nursery!


Meet the pediatricians

Dyan Sharone Hes, MD, FAAP

Consistently named one of New York’s Top Doctors by Castle Connolly since 2010, Dr. Dyan Hes was the founder and medical director of Gramercy Pediatrics in New York City. She served as Clinical Assistant Professor of Pediatrics at the Weill Medical College of Cornell University and at NYU Grossman School of Medicine. Dr. Hes joined Concorde Medical Group in February 2023 and she serves as director of pediatrics at Concorde.

Learn More About Dr. Hes

Daniel Wolloch, MD, FAAP

Daniel Wolloch earned his medical degree from Albert Einstein College of Medicine and then he completed his residency at NYU Bellevue in 1991. He then took time off to spend several years working tirelessly with his autistic son Zachary. After getting Zachary to a point where he was able to finally attend school, Dr. Wolloch then resumed his medical career, first for the Montefiore Medical Group and then at Pedimedica in Teaneck, New Jersey.

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Junko Nishita, MD, PhD

Dr. Nishita is a board-certified pediatrician in the United States and Japan, with an extensive career history in both countries as a physician as well as a researcher. Her professional background includes general pediatrics, pediatric cardiology, molecular biology, neuroscience, and related fields. After completing her pediatric residency in Brooklyn, she joined Gramercy Pediatrics, a private pediatric group practice in 2020 which became part of Concorde Medical Group in 2023.

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Sophia Gigos-Costeas, MD, MPH, FAAP

Dr. Sophia Gigos-Costeas is a born and bred New Yorker who has lived her whole life in the New York Metro area. Prior to joining Gramercy Pediatrics, she worked at Children’s Aid in a variety of roles, including Medical Director, where she guided the Health and Wellness Division through much of the COVID pandemic.


Learn More About Dr. Gigos-Costeas

Gramercy Pediatrics continues to serve the needs of our patients in our new partnership with Northwell Health, Concorde Pediatrics



Our Locations





To reach us at either location, our number is (212) 473-4200