Board of Directors

Siddhartha Sankaran has served as a member of our board of directors since 2021 and the Chairman of our board of directors since June 2026. Mr. Sankaran previously served as the interim Chief Financial Officer at Oscar from January 2023 through August 2023 and Oscar's Chief Financial Officer from March 2019 to March 2021.

Previously, Mr. Sankaran served as the Group Chief Financial Officer & Group Chief Operating Officer of FWD Group Holdings Limited, an insurance company, from September 2023 to July 2026. Before that he served as their Managing Director and Group Chief Financial Officer beginning in September 2023 and as a Senior Advisor from June 2023 to September 2023.

Mr. Sankaran has also had a number of executive roles in the insurance industry including as the Chairman and CEO of SiriusPoint, an international specialty re/insurer, and prior to that served as a member of the board of directors of Third Point Reinsurance Ltd., the predecessor to SiriusPoint. Mr. Sankaran also previously served as Executive Vice President and Chief Financial Officer of American International Group, Inc., or AIG, from February 2016 to December 2018. Prior to that, he served as Executive Vice President and Chief Risk Officer at AIG from November 2010 to February 2016. Mr. Sankaran holds a Bachelor of Mathematics degree, majoring in actuarial science, with distinction from the University of Waterloo.

Mark T. Bertolini is the Chief Executive Officer of Oscar Health, a leading insurer dedicated to making a healthier life accessible and affordable for all. He has served as our CEO and as a member of our board of directors since April 2023.

Mark is former Co-Chief Executive Officer, Chairman, and a member of the board of directors of Bridgewater Associates, the world’s largest and most successful hedge fund.

Mark is also a national health care thought leader, and the former Chairman and CEO of Aetna Inc. At Aetna, Mark assumed the role of CEO in November 2010, and of Chairman in April 2011. In November 2018, he stepped down as Chairman and CEO and served as a Director of CVS Health Corporation upon completion of CVS Health’s acquisition of Aetna, valued at $69 billion. Throughout Mark’s tenure at Aetna, he led the company’s transition from a traditional health insurance company to a consumer-oriented health care company focused on delivering holistic, integrated care in local communities.

Before joining Aetna, Mark held executive positions at Cigna, NYLCare Health Plans, and SelectCare, Inc., where he was President and Chief Executive Officer. He serves as the Chairman of the Board of Directors of Verizon Communications Inc. (communications and technology solutions), and as a director for Thrive Global (sustainable, science-based solutions to enhance well-being, performance and purpose), and the FIDELCO Guide Dog Foundation (non-profit organization that breeds, trains and places German Shepherd guide dogs with people who have visual disabilities).

Mr. Bertolini holds a Bachelor of Science degree in Business from Wayne State University and a Master of Business Administration from Cornell University.

Mr. Gassen has served as president and CEO of Sanford Health, an integrated health system serving communities across the upper Midwest since November 2020 and is an ex officio member of Sanford Health’s Board of Trustees. In addition, he served in a number of leadership roles for Sanford Health over a ten-year period including Chief Administrative Officer, Chief Human Resources Officer and Corporate Counsel. Mr. Gassen is a former healthcare litigator and is a current member of the State Bar of South Dakota. He serves on the Health Systems Committee of the American Hospital Association and is a member of the Healthcare Institute. He holds a Bachelor of Science degree, majoring in criminal justice and religious studies, and a Juris Doctor, both from the University of South Dakota.

Joshua Kushner co-founded Oscar in October 2012, has served as a member of our board of directors since December 2012, and has served as Vice Chair of our board of directors since February 2021. Mr. Kushner is the Founder and Chief Executive Officer of Thrive Capital Management, LLC, a New York-based venture capital firm. Mr. Kushner holds a Bachelor of Arts degree, majoring in Government, from Harvard College and a Master of Business Administration from Harvard Business School.

Ms. Lang has served on our board of directors since 2022. She has served as the Managing Director of Narragansett Ventures, LLC, a strategic advisory firm focused on digital business transformation and growth investing, since January 2014. Since November 2018, Ms. Lang has also served as an adviser to L Catterton. Ms. Lang was the Chief Executive Officer of Time Inc., one of the largest branded media companies in the world, from January 2012 until December 2013. From 2008 until she joined Time Inc. in 2012, Ms. Lang was Chief Executive Officer of Digitas Inc., a global marketing and technology agency and unit of Publicis Groupe S.A. In addition, she headed the company’s pure-play digital agencies, including Razorfish, Big Fuel, Denuo and Phonevalley. Ms. Lang currently serves as a member of the board of directors and the Talent and Compensation and Finance committees of V. F. Corporation, an international apparel and footwear company. Ms. Lang previously served as a member of the boards of directors of Care.com Inc., Nutrisystem, Inc., Benchmark Electronics, Inc. and Vroom Inc. Ms. Lang holds a Bachelor of Arts from Tufts University, majoring in political science, and a Master of Business Administration from the Wharton School of the University of Pennsylvania.

David Plouffe has served on our board of directors since 2021. He previously served as an advisor to the Kamala Harris presidential campaign during 2024. Prior to that, Mr. Plouffe served as a President, Policy and Advocacy of the Chan Zuckerberg Initiative, or CZI, a charitable organization established by Priscilla Chan and Facebook founder Mark Zuckerberg, from January 2017 to November 2019. Prior to joining CZI, Mr. Plouffe served as Senior Vice President of Policy and Strategy of Uber Technologies, Inc., or Uber, a technology-driven transportation company, from August 2014 to January 2017. Before Uber, Mr. Plouffe served in The White House as Senior Advisor to U.S. President Barack Obama from January 2011 to January 2013 and as Campaign Manager for President Obama’s historic campaign victory in 2008. Prior to the Obama White House years, Mr. Plouffe managed and served as the strategist in election efforts of U.S. senators, governors, members of Congress and mayors, and served as the Deputy Chief of Staff to the House Democratic leader on Capitol Hill. Mr. Plouffe has served as a member of the board of directors of the Obama Foundation, a nonprofit organization founded by Michelle Obama and President Obama, since January 2014, and currently serves on the boards of directors of a number of other nonprofit organizations. Mr. Plouffe holds a Bachelor of Arts degree, majoring in Political Science and Government, from the University of Delaware.

Mario Schlosser is the Co-Founder & Advisor to the CEO at Oscar Health.

Previously, Mario served as the President of Technology and Chief Technology Officer at Oscar Health. Prior to that, he served as CEO of Oscar Health, leading the company from inception to serving over 1M members across Individual & Family, Medicare Advantage, and Small Group health plans.

Before co-founding Oscar, Mario also co-founded the largest social gaming company in Latin America, where he led the company's analytics and game design practices. Prior to that, Mario was a Senior Investment Associate at Bridgewater Associates and worked as a consultant for McKinsey & Company in Europe, the U.S. and Brazil.

Mario also spent time as a visiting scholar at Stanford University, where he wrote and co-authored 10 computer science publications, including one of the most-cited computer science papers published in the past decade, in which he developed the EigenTrust Algorithm to securely compute trust in randomized networks. In May 2019, Mario and his co-authors, Sepandar D. Kamvar (Mosaic Building Group Inc) and Héctor Garcia-Molina (Celo), received the prestigious Seoul Test of Time Award from the International World Wide Web Conference Committee (IW3C2) for this work.

Mario holds a degree in computer science with highest distinction from the University of Hannover in Germany and an MBA from Harvard Business School.

Vanessa A. Wittman has served on our board of directors since 2021. She was most recently the Chief Financial Officer of Glossier, Inc., an online beauty product company, from April 2019 to April 2022, and served as an advisor until December 2022. Prior to Glossier, Inc., Ms. Wittman served as Chief Financial Officer of Oath Inc., a digital media company, from January 2018 to January 2019. Ms. Wittman served as Chief Financial Officer of Dropbox, Inc., a cloud storage and collaboration company, from February 2015 to October 2016, and as Chief Financial Officer of Motorola Mobility Holdings, Inc., a consumer electronics and telecommunications company, from March 2012 to February 2015. From October 2008 to March 2012, Ms. Wittman served as Executive Vice President and Chief Financial Officer of Marsh & McLennan Companies, a global professional services company. Prior to Marsh & McLennan Companies, Ms. Wittman held a number of other senior finance roles during her career. Ms. Wittman currently serves on the boards of directors of Booking Holdings since June 2019 and AIG since March 2023. Ms. Wittman previously served on the board of directors of Impossible Foods Inc., a sustainable foods company, from March 2019 to December 2025. From June 2014 to March 2019, Ms. Wittman was a member of the board of directors of Ulta Beauty, Inc., a cosmetics and beauty supply company. She also served as a member of the board of directors of Sirius XM Holdings Inc., an audio entertainment company, from April 2011 to June 2018. Ms. Wittman holds a Bachelor of Arts degree, majoring in Business Administration, from the University of North Carolina at Chapel Hill, and a Master of Business Administration from the University of Virginia.