Executive Leadership Team at Group Health

Group Health's Executive Leadership Team provides senior leadership at Group Health. Their responsibilities include setting long-term strategy, monitoring performance and overseeing day-to-day functions.

Scott Armstrong

President and chief executive officer
Group Health Cooperative

Scott ArmstrongScott Armstrong is president and CEO of Group Health Cooperative, one of the nation's largest consumer-governed health care systems. He has been with Group Health since 1986 in positions ranging from assistant hospital administrator to chief operating officer. He became president and CEO in January 2005.

Armstrong has more than 30 years of experience in health care. He joined Group Health from Miami Valley Hospital in Dayton, Ohio, where he was the assistant vice president for hospital operations.

He received a bachelor's degree from Hamilton College in New York and a master's degree in business with a concentration in hospital administration from the University of Wisconsin-Madison.

Armstrong joined the board of directors of Puget Sound Energy (PSE) in 2015. PSE has provided energy to the Puget Sound area for more than 135 years.

Armstrong is a commissioner of the Medicare Payment Advisory Commission, board member of the Alliance of Community Health Plans, and a board member of America's Health Insurance Plans. He is also a fellow of the American College of Healthcare Executives.

Diana Birkett Rakow

President, Group Health Foundation
Executive vice president, Marketing and Public Affairs, Group Health Cooperative

Diana Birkett RakowDiana Birkett Rakow is executive vice president of Marketing & Public Affairs for Group Health and president of the Group Health Foundation. As executive vice president, she is responsible for driving delivery of aligned and consistent messaging in Marketing & Public Affairs to promote the organization's services and products, enhance its brand and reputation in the communities it serves, and support its business goals and mission of improving health. As president of the Foundation, she oversees their work to support Group Health patient care and community health programs.

Prior to joining Group Health in 2006, Rakow served in Washington, D.C. as health policy advisor to the Democratic staff of the United States Senate Committee on Finance, which has jurisdiction over Medicare and Medicaid, and to Senator Max Baucus (D–Montana), the ranking member of the committee.

Rakow was a David Winston Health Policy Fellow in Washington, D.C., following graduate school at the University of Washington, where she received master's degrees in public health and public administration. In addition, she received a Bachelor of Arts in Chemistry from Harvard University. She currently serves as an affiliate associate professor at the University of Washington School of Public Health. She is also a member of the Washington State Health Innovation Leadership Network and sits on the board of directors for the Washington Vaccine Association, Pacific Science Center, and Seattle Metropolitan Chamber of Commerce.

Chris Knackstedt

Executive vice president and chief financial officer

Chris KnackstedtChris Knackstedt is executive vice president and chief financial officer (CFO). He is responsible for all aspects of finance at Group Health Cooperative.

Prior to joining Group Health, Knackstedt served as CFO for MultiCare Health System, a nonprofit integrated health care system spanning four counties in the South Puget Sound area of Washington state. He has also served as CFO at health organizations that include Mercy Health, Centura Health/St. Anthony Health System, and Sierra Providence Health Network. In addition, he has worked on the insurance side of health care with Great-West Life and Annuity, Healthcare Division. His accomplishments included strengthening network development and management across multiple regions, improving service, processing, analytics, and financial performance.

Knackstedt holds an MBA from the University of Texas at El Paso, and a bachelor’s degree in accountancy with a minor in economics from New Mexico State University. He is a CPA.

Sue Kozik

Executive vice president and chief information officer

Sue KozikSue Kozik is executive vice president and chief information officer (CIO). She is responsible for Group Health's IT framework and guiding the IT strategy and technology investments for the organization. She also leads efforts to bring together all IT-related functions, including Enterprise IT, Care Delivery IT, Informatics, and Business Technology Services. 

Kozik has more than 30 years in information technology experience across a diverse mix of service industries. Most recently, she was senior vice president and CIO at Independence Blue Cross in Philadelphia. She has also served in executive roles at TIAA-CREF, Lucent Technologies, and CIGNA.

Kozik graduated with a bachelor's degree in history from Bates College. She currently serves on the Bates College Board of Trustees, the Advisory Board of TaaSera, and Tech Impact's Board of Directors.

Tami Lamp

Executive vice president
Human Resources

Tami LampTami Lamp is executive vice president of Human Resources for Group Health Cooperative. She is responsible for developing key human resources initiatives that support the strategic plan and vision of the organization.

Prior to joining Group Health in 2015, Lamp was the chief people officer for Caradigm, a Bellevue-based global software company focused on population health. She has also held HR leadership positions at Microsoft, Starbucks, WRQ, and HomeGrocer.com.

A native Northwesterner, Lamp earned a master's degree in industrial and labor relations from Cornell University, a master's degree in aeronautical studies and business administration from Embry-Riddle Aeronautical University, and a bachelor's degree from the University of North Dakota.

Erin Leff

Executive vice president
Group Practice Division

Erin LeffErin Leff is executive vice president of the Group Practice Division at Group Health Cooperative. She is responsible for the strategic planning and operations of 25 medical centers, including 3 multispecialty campuses. In addition, she oversees one of the region's largest pharmacy systems, lab and radiology operations, occupational health programs, and behavioral health services.

Leff has 20 years of experience in diverse health care settings, including Planned Parenthood, a national network of nonprofit community clinics, and Tenet Healthcare, a publicly-traded hospital system. Prior to joining Group Health in 2003, she was the associate administrator at Tenet's Hahnemann University Hospital in Philadelphia, Pa.

Leff received a bachelor's degree from Colgate University in New York and a master's degree in business administration with a concentration in health sector management from Duke University's Fuqua School of Business. She has participated in numerous leadership development programs, including Tenet's Future CEO Development Program and Leadership Tomorrow Seattle. She currently serves on the board of the Washington State Hospital Association.

Dawn Loeliger, JD

Executive vice president
Strategic Planning & Deployment

Dawn LoeligerDawn Loeliger provides executive leadership for strategic planning, strategic business development, Lean consultancy, enterprise project management, and capital and facility planning.

Loeliger has nearly 30 years of leadership experience. Since joining Group Health in 2011, she has served as executive director, Marketing Operations and Innovation; and executive director, Business Management. One of her accomplishments in 2013 was to co-lead the Cost Repositioning Team, where she demonstrated her ability to oversee the implementation of challenging, controversial initiatives across the organization. She has also worked as a senior vice president at Hitachi Consulting, overseeing the global Microsoft account; and held leadership positions with Microsoft, MyPoints.com, and M/A/R/C Inc.

Loeliger has a juris doctorate with honors from Southern Methodist University. She earned a masters in marketing research and a bachelor's in English — graduating magna cum laude — from the Universty of Georgia.

Robert O'Brien

Executive vice president
Health Plan Division

Robert O'Brien

Robert O'Brien is responsible for Group Health's health plan operations, including line of business management, product management, network services and care management, sales and account management and administration. O'Brien was previously with Mercer, where he led the health and benefits consulting business in the Americas, and chaired the global practice.

O'Brien holds an AB degree, magna cum laude, from Harvard University and a JD degree from the University of Maine School of Law. He is an active member of the Oregon State Bar, the American Bar Association, the American Health Lawyers Association, and the National Business Group on Health. Bob also serves on the board of trustees and executive committee of the Seattle Metropolitan Chamber of Commerce and is a director emeritus of the Washington Health Alliance, the Benaroya Research Institute, and the Seattle Symphony.

Paul Sherman, MD

Executive medical director
Health Plan Division

Medical director
Care Systems Development
Group Health Physicians

Paul Sherman, MDPaul Sherman, MD, leads the process of optimizing Group Health's health plan and care-delivery capabilities. He began clinical practice at Group Health in 1992, and his previous roles include associate medical director of Strategy Deployment, medical director of Consultative Specialty Services, Seattle district medical director, and chief of Pediatrics.

Dr. Sherman is a board-certified pediatrician with a Bachelor of Science from the University of Notre Dame and a Doctorate of Medicine from Johns Hopkins University School of Medicine. He completed his internship and residency at Seattle Children's, and obtained his Master of Health Administration at the University of Washington. He currently serves on the Giddens School board of trustees and on the board of directors for Seattle Counseling Services.

Stephen Tarnoff, MD

President and chief medical officer
Group Health Physicians

Executive medical director
Group Practice Division

Stephen Tarnoff, MDStephen Tarnoff, MD, is executive medical director of Group Health Medical Centers, overseeing the care of nearly 400,000 patients who are served in Group Health Cooperative's 25 owned and operated facilities.

Dr. Tarnoff has been with Group Health since 1981, practicing as a family physician for more than 25 years. He has held numerous leadership roles in Primary Care, Consultative Specialty Services, and as medical director for the Group Practice Division. Before his current role, he was medical director for Medicare and Medicaid, and acting medical director for Group Health's Western Washington contracted network. 

Dr. Tarnoff graduated from University of California, Berkeley, and earned his medical degree from the University of Southern California School of Medicine. He completed his residency at the University of Washington and a fellowship in medical education and health policy at the Association of American Medical Colleges. He is a member of the Washington Academy of Family Physicians and the Washington State Medical Association.

Sally Yates

Executive vice president and general counsel

Sally YatesSally Yates is executive vice president and general counsel for Group Health Cooperative. She directs Enterprise Risk and Governance, responsible for legal, privacy, compliance, audit, risk management, information security, and governance services.

Yates has been with Group Health since 1991, first helping to build Group Health's in-house litigation practice and later branching into other areas of legal practice and assuming oversight of all risk and governance functions.

Before joining Group Health, Yates was a litigator and employment law attorney at Davis Wright Tremaine. She received her law degree from the University of Virginia School of Law and a bachelor's in history, graduating magna cum laude, Phi Beta Kappa, from Carleton College. She is a member of the Washington State Bar Association, The American Health Lawyers Association, and the Washington State Society for Healthcare Attorneys. She is also a member of the board of directors of the Alliance for Education, and serves as a mentor to graduate students in the University of Washington Master of Health Administration program.

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