LEADERSHIP

The Firefly Team

Change in healthcare demands vision and persistence. Heart and resilience. Our leadership infuses the Firefly culture with a balance of focused intensity, genuine caring, and earned wisdom.

Our leadership

Fay Rotenberg

Prior to Firefly, Fay initiated Premji Invest’s U.S. healthcare growth equity investments. She co-founded and served as CEO of Mymo, bridging the gap between excess physician capacity and patient demand. Fay was also a partner at LG's venture fund, investing in health and enterprise software companies, and she led AetherWorks’ first spin-off. Fay attended Georgetown University.

Fay Rotenberg
Chief Executive Officer
Andy Ellner

Andy co-founded Firefly because he believes everyone deserves access to high-quality care. He was the founding co-director of Harvard’s Center for Primary Care and their Program in Global Primary Care and Social Change. He earned his MD from Harvard Medical School and MSc from the London School of Economics. Andy completed his medical training at Brigham and Women’s Hospital.

Andy Ellner
MD, MSc
Chief Clinical advisor
Jeff Greenberg

Before co-founding Firefly, Jeff served as a medical director and primary care physician at Brigham and Women’s Hospital. He was also an assistant professor of medicine at Harvard Medical School. Jeff earned his MD and MBA from the University of Pennsylvania. He completed his medical training at Massachusetts General Hospital.

Jeff Greenberg
MD, MBA
Chief Network Officer
Nisha Basu

Nisha has dedicated her career to providing patients the individualized care and support they deserve. She is a part-time lecturer at Harvard Medical School. Before joining Firefly, she worked as a primary care physician and innovation leader at Beth Israel Deaconess Medical Center. She earned her MD and MPH from Tufts University and studied biomedical engineering at Tulane University.

Nisha Basu
MD, MPH
vice president, clinical
Stuart Battersby

Previously, Stuart was the first non-founder executive at Sidecar Health. He led three rounds of funding to launch a full-risk ACA and large employer product with instant cash pay and price transparency. Stuart was also CEO and president of Amerigroup Washington’s Medicaid health plan. He guided a full-state procurement that resulted in statewide integration of physical and behavioral health services.

Stuart Battersby
Chief Financial Officer
Liz Kellogg

Prior to Firefly, Liz was chief marketing officer at Buoy Health, a digital navigation and health benefits marketplace. She built Buoy’s entire marketing function, launching four new products while driving engagement and adoption among employees and consumers. Liz also spent 10 years leading marketing teams at athenahealth. She earned her BA in Philosophy from the University of Vermont.

Liz Kellogg
Chief Marketing Officer
Kristin Kelly

Kristin was formerly the AVP of family and individual plans at Bright Healthcare, where she led new market selection, product development and implementation, and go-to-market strategy across 16 states. Kristin also worked in consulting and policy for Navigant, MNsure, United Healthcare, and others. She earned her MPH from Tulane University and her BA from the University of Pennsylvania.

Kristin Kelly
MPH
vice president, growth
Matthew Libby

After starting a career in physics and education, Matthew changed directions to become a primary care doctor. He spent seven years practicing in a rural community health setting on Cape Cod, helping to grow and improve the organization while also teaching students. Matthew is also a clinical instructor in family medicine and community health at University of Massachusetts Medical School.

Matthew Libby
DO
Medical Director
Brian Lynch

Before joining Firefly, Brian was Aledade’s founding general counsel and senior vice president of legal. He was also a clerk for the 6th Circuit U.S. Court of Appeals, counsel to the governor of Michigan, and worked in Credit Suisse’s Customized Fund Investment Group. Brian earned his JD from the University of Michigan and BS degrees in Economics and Physics from Michigan State University.

Brian Lynch
JD
General Counsel
Evan Wittry

Evan brings a wealth of technology leadership experience from prior roles at athenahealth, RazorInsights, and Navicure. He earned his BS in Computer Science from the University of Georgia.

Evan Wittry
chief technology officer

Our board of directors

Jonathan Bush

An American technology entrepreneur, Jonathan is best known as the cofounder and former CEO of athenahealth. He is Firefly Health’s executive chairman and a board member at SonderMind and Innovaccer.

Jonathan Bush
Founder & Chief Executive Officer, Zus Health
Nancy Brown

Nancy joined Oak HC/FT in 2014, focusing on growth equity and early-stage venture opportunities in healthcare. She currently serves on the boards of Cricket Health, Firefly Health, Groups Recover Together, Maven, and Unite US. Nancy is also actively involved with Noom, Wayspring, and TurningPoint. Prior investments include Limeade.

Nancy Brown
General Partner, Oak HC/FT
Carl Byers

Carl brings significant operating experience in healthcare IT to his role as Partner. He was on the founding team at athenahealth, where he served as CFO from 1997 to 2010 and led their 2007 IPO. Prior to athenahealth, Carl was a senior consultant in Booz, Allen & Hamilton’s New York office, where he worked in the financial services and health insurance industries.

Carl Byers
Partner, F-Prime Capital Partners & Adjunct Lecturer, Harvard University
Seth Cohen

Prior to OODA Health, Seth was vice president of sales and alliances at Castlight Health, where he led their market partnerships and key national accounts team. He was also on Castlight’s leadership team and currently serves as a board member. Before Castlight, Seth was a management consultant at McKinsey & Company and a founding member of their Center for Healthcare Reform.

Seth Cohen
Co-Founder & CEO, OODA Health
Andy Ellner

Andy co-founded Firefly because he believes everyone deserves access to high-quality care. He was the founding co-director of Harvard’s Center for Primary Care and their Program in Global Primary Care and Social Change. He earned his MD from Harvard Medical School and MSc from the London School of Economics. Andy completed his medical training at Brigham and Women’s Hospital.

Andy Ellner
MD, MSc
Chief Clinical advisor
Fay Rotenberg

Prior to Firefly, Fay initiated Premji Invest’s U.S. healthcare growth equity investments. She co-founded and served as CEO of Mymo, bridging the gap between excess physician capacity and patient demand. Fay was also a partner at LG's venture fund, investing in health and enterprise software companies, and she led AetherWorks’ first spin-off. Fay attended Georgetown University.

Fay Rotenberg
Chief Executive Officer
Julie Yoo

Julie leads investments in healthcare technology, focusing on companies that modernize how we access, pay for, and experience healthcare. Previously, Julie was the co-founder, chief product officer, and board director at Kyruus, a market leader in patient access. She helped scale the business to reach 20M patients and over 225,000 healthcare providers in the U.S.

Julie Yoo
General Partner, Andreessen Horowitz

Our advisory council

Brian Marcotte

At the Business Group, Brian established the Health Innovations Forum to accelerate market traction for promising digital health startups. He also created the Executive Committee on Value Purchasing, a cross-industry council focused on shifting the market toward value-based pricing and provider accountability. Previously, Brian was vice president of compensation and benefits for Honeywell International.

Brian Marcotte
Former president and CEO, Business Group on Health; Firefly Advisory Council Chairman
Karyn Polito

Karyn Polito is a businessperson, attorney, and government leader. As the 72nd Lieutenant Governor of Massachusetts from 2015 to 2023, she advocated for women's empowerment and championed renewable energy, climate adaptation, workforce development, housing, and the innovation economy. Previously, Karen was a member of the Massachusetts House of Representatives and partner at Milton, Laurence & Dixon, LLP.

Karyn Polito
Former Lt. Governor of Massachusetts
Marcus Osborne

In addition to leading RightMove Health, Marcus Osborne is on the board of directors of five early-stage wellness and healthcare companies, serving as executive chairman of one of them. Previously, he was senior vice president of Walmart Health. Before earning his MBA at Harvard in 2007, Marcus interned at the White House and served as CFO of the Clinton Foundation’s HIV/AIDS Initiative.

Marcus Osborne
CEO, RightMove Health
Manny Menendez

At MJ Advisor Group, Manny supports client growth imperatives through consulting engagements and front-line sales support. He grounds his approach in respect, authenticity, and trust. Previously, he served as chief revenue officer (CRO) for ConsumerMedical, leading 4 consecutive years of double-digit growth and spearheading efforts to integrate all growth functions after acquisition by Alight.

Manny Menendez
Principal, MJ Advisor Group
Erik Sossa

Erik Sossa is an independent consultant working with employers, industry groups, and healthcare providers to expand access to effective, affordable healthcare for employees. Previously, he led PepsiCo’s strategy, design, and financial optimization of health and insurance, retirement, and wellness programs around the world. Before joining PepsiCo, he was a consultant with Mercer Human Resource Consulting.

Erik Sossa
Former vice president of global benefits and wellness, PepsiCo
Matt Manders

Throughout his successful 30-plus-year career at Cigna, Matt Manders worked to transform the company into a leader in essential health care services focused on creating an outstanding overall experience for each customer. He led efforts to enable Cigna businesses to rapidly deliver value to the market, while ensuring the organization continuously struck a balance between access, quality, and cost of care.

Matt Manders
Former president of strategy, solutions, and U.S. markets, Cigna Corporation
Ron Fontanetta MBA, MPH

Ron Fontanetta advises market-leading healthcare companies on strategic business planning, marketing, product development, and talent acquisition. He has spoken at seminars sponsored by NBGH, Canadian Pension and Benefits Institute, ECFC, and The Conference Board. Often quoted by the national business press, Ron has appeared on CNN, CBS Evening News, CNBC, Bloomberg News, and ABC World News Tonight.

Ron Fontanetta MBA, MPH
Former North America health and benefits practice leader of strategic growth, Willis Tower Watson

Our investors

a16zF-Prime CapitalOak HC/FT