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Health Net Leadership


Brian Ternan - Chief Executive Officer and Plan President

Brian Ternan

Chief Executive Officer and Plan President

Brian Ternan is president and chief executive officer for Health Net, a wholly owned subsidiary of Centene Corporation. In this role, he oversees Health Net's commercial and government businesses in California. Ternan is an industry leader with more than 25 years of health plan experience in commercial, labor and group Medicare business.

Ternan joined Health Net in September 2019, after four years as the commercial plan president for Anthem Blue Cross of CA. Prior to that, he served as president of Aetna's Western region and had P&L responsibility for group, individual, group Medicare and public and labor lines of business. During his nine-year tenure at Aetna, Ternan also served as president of Aetna’s Southern California market; president of the West region national accounts; and vice president of Southern California national accounts.

Prior to Aetna, Ternan held various positions at Mercer HR Consulting throughout the West. At Mercer, he advised large employers about the various aspects of their human resource strategies.

Ternan also serves on the board for California Association of Health Plans, Greater Sacramento Economic Council, National Hispanic Medical Association, CalChamber and Song for Charlie. He’s the executive sponsor for I.N.S.P.I.R.E., Centene’s enterprise-wide women’s network.

Ternan earned a Bachelor of Arts from California Polytechnic State University, San Luis Obispo, California.


Martha Santana-Chin - Medi-Cal and Medicare President

Martha Santana-Chin

Medi-Cal and Medicare President

Ms. Santana-Chin currently serves as Government Programs Officer for Health Net in the California Market. She is a managed care leader with nearly three decades of experience in managed care, healthcare service operations, delivery system strategy, provider relations, network management and more. She has designed and led transformational programs to improve access to care for California’s most vulnerable residents, advance health equity and manage costs. Her extensive healthcare leadership experience includes working with independent physician practices, hospitals, federally qualified health centers and health plans, serving Medi-Cal and low-income communities. 

In her current role, Ms. Santana-Chin leads the company’s Medicare and Medi-Cal business lines, which serve over 2 million members. She is accountable for long-term strategic planning, operations and the successful execution of annual plans to deliver high-quality affordable care. To help ensure that Health Net meets the unique needs of local communities, she collaborates with leaders in the healthcare delivery system and community stakeholders, She also supports and oversees implementation of the company’s product growth and service area expansions.

Community-minded, Ms. Santana-Chin serves on the Board of Directors of the United Way of Greater Los Angeles and is member of the Board of Directors and Executive Committee of the Integrated Healthcare Association. She is also a member of the Executive Diversity and Inclusion Council for Centene. Ms. Santana-Chin holds a Bachelor of Science in Business Finance from California State University, Long Beach and a Master’s degree in Business Administration from the University of California, Irvine.


Jessica Sellner - Chief Financial Officer

Jessica Sellner

Chief Financial Officer

Jessica Sellner is the chief financial officer for Health Net. She leads the financial planning and actions for the company with a focus on the company's financial strengths. Her leadership scope includes forecasting and budgeting, financial planning and analysis, healthcare analytics and commercial pricing.

Sellner joined Health Net in August 2014 as director of finance. Serving in increasingly responsible finance roles since then, including vice president of finance for all lines of business, she most recently served as interim CFO. Her financial skills, as well as knowledge of the California health care markets, are core to her leadership role.

Sellner serves numerous organizations throughout the greater Sacramento region, including as a board member for United Way and an inaugural year board member for the West Park Junior Panthers. She is also involved in her local basketball community and volunteers as a bookkeeper at a Montessori school.

Sellner earned a Bachelor of Science from California State University, Chico, and a master's degree from the University of Nevada, Reno.


Alex Y. Chen - Chief Medical Officer

Alex Y. Chen

Chief Medical Officer

Alex Chen is chief medical officer at Health Net, LLC. In this role, Dr. Chen leads and provides oversight of Health Net teams responsible for the Medical Affairs & Quality department. Prior to joining Health Net, Dr. Chen served as CMO at AltaMed Health Services, responsible for overall medical and utilization management. Prior to that, he held executive positions with AltaMed overseeing quality and safety. He’s taught and conducted research at Keck School of Medicine of USC as an associate professor of pediatrics, splitting his time between research and clinical activities. His major area of research interest is health care access and quality.

Dr. Chen earned his Doctor of Medicine from Harvard Medical School, his Master of Science from University of California, Los Angeles, and a Bachelor of Arts from Northwestern University. He is board-certified in pediatrics and licensed in California, where he has practiced part time since he completed his residency at UCLA.


Dr. Pooja Mittal - Chief Health Equity Officer

Pooja Mittal

Chief Health Equity Officer

Dr. Pooja Mittal is the chief health equity officer for Health Net. She leads the company in developing, implementing, facilitating and embedding health-equity, strategic initiatives into every aspect of Health Net's programs, services actions and outcomes. Dr. Mittal joined the company in June 2016.

In addition to her role as chief health equity officer, Dr. Mittal practices primary care at a Federally Qualified Health Center in San Mateo County and works at the National Clinicians Consultation Center at University of California, San Francisco. As a family physician and recognized national expert on perinatal HIV care, she has a unique perspective to design strategic initiatives that improve care for California's most vulnerable populations.

Dr. Mittal also dedicates her time to increasing health equity through teaching the next generation of medical residents. She is an adjunct associate professor at University of California, San Francisco and Stanford University School of Medicine. In addition to her clinical work, she’s published her work in the areas of well-childcare, group visits, preconception care, health equity and perinatal HIV.

Dr. Mittal earned her Bachelor of Science from Boston University and her Doctor of Medicine from A.T. Still University of Health Sciences.


Christy K. Bosse - Senior Vice President and CA Compliance Officer

Christy K. Bosse

Senior Vice President and CA Compliance Officer

Christy Bosse joined Health Net in November 2004. She currently serves as the CA compliance officer responsible for the combined Health Net and California Health & Wellness health plan. In this role, she is responsible for the overall compliance program in the CA market covering all lines of business offered.

Prior to her current role, Bosse served as the Medi-Cal compliance officer specific to the Health Net and CA Health and Wellness' Medicaid lines of business from 2015-2018. She focused on compliance for Health Net's commercial lines of business from 2008-2015.

Bosse graduated from University of California, Los Angeles, earning two Bachelor of Arts degrees. She also holds a Master of Business Administration.


Darrel Ng - Vice President, Communications and Marketing

Darrel Ng

Vice President, Communications and Marketing

Darrel Ng is vice president of communications at Health Net, LLC. In this role, Ng leads and provides oversight for Health Net teams responsible for marketing and communications on behalf of Health Net and California Health & Wellness. He brings more than two decades of experience providing strategic communications counsel to political, government and corporate leaders across the country. He’s an expert in leading public affairs, corporate communications and marketing teams in the health care payer, provider and digital health space. In 2021, Ng helped the state of California to lead COVID-19 vaccine communications for 4 months, leading the country's most successful vaccine rollout program.

Prior to joining Health Net, Ng founded Fast Twitch Communications, a health care-focused strategic communications firm. He also held senior positions at W2O Group and Anthem, Inc. Ng is a seasoned professional in the world of campaign politics and health policy. He has worked on three presidential campaigns – most recently as the director of vice-presidential rapid response for the Romney campaign in 2012. He has also served as a spokesperson for Gov. Arnold Schwarzenegger and the California Department of Insurance.

Ng earned a Bachelor of Arts from University of California, Berkeley.


David Koenig

Vice President of Government Relations, Public Affairs & Community Investments

David Koenig is vice president of government relations, public affairs & community investments at Health Net. He manages a portfolio of community, political and infrastructure investments. He also oversees a diverse team of staff and consultants who, at the state and local level, work to improve Health Net's health care services with community and government entities. 

Prior to Health Net, Koenig advised Centene Corporation in California for more than 10 years as the principal at his consulting firm, Koenig Consulting LLC. Koenig served as a senior strategist, campaign and coalition-building manager to corporate, non-profit, pro-bono and labor clients on legislative advocacy campaigns and community engagement. He managed successful budget advocacy campaigns to secure millions from the California state budget. 

Koenig holds a Bachelor of Arts from California State University, Northridge. He’s also served on the boards of San Fernando Valley Young Democrats, Democratic Party of the San Fernando Valley and Californians for the Support of Early Education. 

Last Updated: 08/30/2024