Meet Our Administrative Team

Greg Serrao

Greg Serrao


He is the President of Colony Care Behavioral Health. He is the founder and a board  member of Thrive Skilled Pediatric Care (Thrive SPC), a provider of pediatric home care services to  medically fragile children. He served as the Chairman and CEO of Thrive SPC from April 2016 to  July 6, 2020. Prior to Thrive SPC, he founded American Dental Partners, Inc. (ADPI), and served  as the company’s CEO and President and a Director for twenty years. In July 2015, he retired as CEO and President of ADPI. He remained Chairman of ADPI until June 2021. From 1992 through December 1995, he served as the President of National Specialty Services, Inc., a subsidiary of Cardinal Health, Inc. From 1991 to 1992, he served as Vice President of Corporate Development at  Cardinal Health. Before joining Cardinal Health, he was an investment banker at Dean Witter  Reynolds Inc., where he co-founded its health care investment banking group and specialized in mergers,  acquisitions, and public equity offerings. He serves on the Board of Directors of National Institute for Children’s Health Quality (NICHQ) and LearnWell. He is a Senior Advisor to Amulet Capital Partners.  He is the former President of the Boys and Girls Club in Lawrence, MA, former member of the Dean’s  Board of Advisors at Tufts University School of Dental Medical, former member of the Dean’s Advisory  Board at the Harvard School of Dental Medicine, and a former member of the Finance Committee for the  Town of Andover.

Mark Geer

Mark Geer, Ed.D.



Mark Geer received his bachelor’s in Psychology from the University of Maine in 1973 and his doctorate in Counseling Psychology from Boston University in 1981. Dr. Geer co-founded Colony Care Behavioral Health in 1994. He has held positions as Chief Psychologist and Director of Training in Psychology at Bournewood Hospital and Clinical Instructor in Psychiatry at Tufts University Medical School. Dr. Geer specializes in adult and adolescent psychotherapy, hypnotherapy, and marriage counseling.

See Dr. Geer’s profile in the Psychology Today Therapist Finder Directory.


Paula Joaquin, LCSW


Director, Payor and Clinician Relations

Paula J. Joaquin has been a vital resource to Colony Care Behavioral Health for 30 years. The owner and operator of Billings & Collections, LLC, Paula provides consulting services to Colony Care Behavioral Health in the role of Director, Payor and Clinician Relations. Paula provides medical billing, collections, insurance panel credentialing and other services to Colony Care Behavioral Health.  Paula received a BS from the University of Massachusetts and a Masters in Social Work from Simmons University.

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