The community at Groups begins with the people who deliver treatment every day. Our team is diverse, with a range of personal and professional backgrounds, but we share a set of core values:

  • Purpose: We believe in improving healthcare for the underserved.

  • Empathy: We are inspired by people brave enough to change their lives.

  • Innovation: We are redefining the way recovery is achieved and measured.

  • Action: We know time is of the essence.


Gregg Fairbrothers, President / Chairman

Gregg taught for over a decade at the Tuck School of Business at Dartmouth College. His wildly popular entrepreneurship class made him a favorite mentor among students. Previously, Gregg founded the Dartmouth Entrepreneurial Network and served as its Director for 14 years. In 2004 he founded the Dartmouth Regional Technology Center (DRTC), Inc. a 55,000 sq. ft. incubator developing technology-based innovations with the potential for significant social impact. 

Mr. Fairbrothers has more than 22 years experience in almost all operational and investment-related aspects of the upstream oil and gas industry, from exploration through IPO. He was President and founder of a mid-sized international oil and gas producer, Samson International. 

Mr. Fairbrothers graduated Dartmouth magna cum laude in 1975 with a B.A. in Earth Sciences. He also earned an M.S. degree from Rutgers University in Geology in 1977, and an MBA from the University of Tulsa in 1983.

Dr. Jeff De Flavio, MD, Founder

Jeff is the founding CEO of Groups. His research focuses on how to expand access to drug treatment in primary care and he has experience leading healthcare teams in resource-constrained settings. Jeff holds an MD from Dartmouth Medical School and an MBA from The Tuck School of Business at Dartmouth. He also holds a B.A. in Philosophy from the George Washington University. Prior to becoming a physician, Jeff worked at a hospital in West Africa, Partners In Health, and a boutique investment bank. 

Joy Sun, COO / Co-Founder

Joy serves as Chief Operating Officer, with responsibility for growth and operations across markets. Prior to joining Groups, she was COO at GiveDirectly, a first-of-its-kind nonprofit that pioneered a new approach to international aid. Joy previously was a manager at McKinsey & Company in the healthcare and agriculture practices, and was Director of Operations at the Clinton Health Access Initiative, where she helped design and implement large-scale HIV treatment programs. She holds an MBA from Stanford Graduate School of Business and a B.S. from Georgetown University.

Josh Willeford, CFO

Josh serves as Chief Financial Officer, with responsibility for accounting, finance, revenue cycle, human resources, and IT across markets. Prior to joining Groups, Josh was Vice President at Optum – Provider Advisory Services where he led consulting engagements designed to provide a holistic view of the integrated care delivery system by providing clients with financial analysis and modeling, budgeting and forecasting, patient access improvement initiatives, and physician compensation plan redesign. Josh previously was a VP at Advisory Board Company, finance director at, and an accounting manager at Surgis, Inc. He holds a MAcc from the University of Tennessee in Knoxville and a B.S. from Lipscomb University.

Dennis Reaves, CIO

Silas Howland, Co-Founder

Cooper Zelnick, Executive Director

Jeremy Carpenter, Executive Director