Senior Leadership Team

Scott E. Coffin, Chief Executive Officer

Scott E. Coffin is the Chief Executive Officer (CEO) for Alameda Alliance for Health (Alliance), a publicly operated safety-net health plan that serves more than 270,000 residents in Alameda County. The Alliance is a public entity that is governed by a 15 member Board of Governors appointed by the Alameda County Board of Supervisors. As CEO, Mr. Coffin oversees the entire operation of the health plan and ensures that all Alliance members receive timely access to quality health care and the highest levels of customer service. He has more than 22 years of experience in health care leadership, including health plan management and hospital administration, and has dedicated the last decade of his career to integrating Medicare and Medicaid services, innovating shared savings and gainsharing arrangements, and implementing quality improvement programs. Mr. Coffin serves as a Board Member of Local Health Plans of California and First 5 Alameda County, and continues to develop partnerships with providers that lead to improving the quality of life.

Prior to joining the Alliance, Mr. Coffin served as the Executive Director for Anthem Blue Cross, Northern CA and oversaw the $1.1B operations for over 500,000 Medi-Cal members in 18 urban and rural counties in Northern California. Mr. Coffin founded the DeSante Group LLC, a health care consulting firm that delivered Medicaid and Medicare integration services to state health agencies, health plans, hospitals and physician groups. He also has held leadership positions with the Health Plan of San Joaquin, Blue Shield of California, Sutter Health Hospitals, and Vision Service Plan. Mr. Coffin earned his degree in business administration at California State University in San Bernardino, and continued his professional development and education at Dartmouth College Tuck School of Business.


Matthew Woodruff, Chief Operations Officer


Matthew Woodruff is the Chief Operations Officer at Alameda Alliance for Health (Alliance), with responsibility for all health plan ongoing operations, providing oversight to Claims, Community Relations, Contracting, Credentialing, Data Validation, Facilities, Member Services, and Provider Services. Over the past year, Matthew has worked to reorganize his internal departments and create promotional opportunities for his teams and departments. He has also worked to update and improve the facilities and overall physical workplace environment.

Matthew's experience as a leader in health care has garnered him recognition as Distinguished Service Awardee from the Department of Health and Human Services. He also serves as the Chair of the Membership and Registration Committee for his sons’ local Boy Scouts chapter.

Matthew lives in San Jose, California with his wife, Maria and their two children. When he is not working he enjoys jogging, reading and spending time with his family. Matthew attended St. Mary’s College in Moraga, California and earned degrees in psychology and religious studies.


Steve O'Brien, MD, Chief Medical Officer


Steve O’Brien, MD is the Chief Medical Officer at Alameda Alliance for Health (Alliance) with responsibility and oversight for Medical Management and Quality, extending from quality improvement to utilization management. In this role, Dr. O’Brien’s focus is to ensure that the Alliance continually delivers programs with quality care and service which will improve the quality of life for Alliance members.

Under Dr. O’Brien’s leadership, the East Bay AIDS Center grew to the largest HIV program in the San Francisco East Bay.  At Alta Bates Summit Medical Center, Dr. O’Brien led significant improvement in Quality and Physician Satisfaction scores as well as developing Sutter’s largest 340B pharmacy program. He is a member of the American Academy of HIV Medicine Board of Directors and the California State HIV Medical Advisory Committee. He has been recognized with service and quality awards from Sutter, Alta Bates Summit Medical Staffs and was recognized by Alameda County Office of AIDS Administration as provider of the year for outstanding contributions to HIV care in the community.

Dr. O’Brien is a 20 year resident of El Cerrito, California where he enjoys hiking in the East Bay hills with his dog and with friends. Dr. O’Brien trained at the University of Washington, where he earned BA, BS and MD degrees, before moving to the Bay Area in 1990 for residency training at UCSF in Internal Medicine.  After several years on faculty at UCSF, he became Medical Director at the East Bay AIDS Center.  From 2011 through 2017, he served as Chief Medical Officer at Sutter’s Alta Bates Summit Medical Center in Berkeley and Oakland until joining Alameda Alliance for Health as Chief Medical Officer in January 2018. 


Gil Riojas, Chief Financial Officer


Gil Riojas is the Chief Financial Officer at Alameda Alliance for Health (Alliance), with responsibility for the overall financial management of the Alliance. This includes oversight of financial budgeting and forecasting, financial reporting, vendor management and statutory compliance as well as other related activities.

Prior to joining the Alliance, Gil worked for more than 15 years at the California Department of Managed Health Care (DMHC) where he oversaw the Financial Review Office and was responsible for monitoring the financial solvency and compliance of over 124 managed care plans in California. Gil also served as an expert reporting to the Department’s Financial Solvency Standards Board and created the Department’s first comprehensive financial analysis report of Local Initiative and County Organized Health Plans. Gil currently volunteers as a board member for Bay Area Wilderness Training (BAWT), a local non-profit organization whose mission is to create equitable access to outdoor experiences for youth of color and low-income youth.

Gil lives in the East Bay and when he is not working, he enjoys spending time with his family, hiking, mountain biking and generally all things outdoors. Gil attended Pacific Union College and earned his Bachelor of Science degree in Business Administration. He is a Certified Public Accountant, a member of the California Society of Certified Public Accountants and of the American Institute of Certified Public Accountants.


Tiffany Cheang, Chief Analytics Officer

Tiffany Cheang is the Chief Analytics Officer at Alameda Alliance for Health (Alliance), with responsibility for company-wide reporting and analytics to support and ensure data driven decision making across the organization. Prior to joining the Alliance in early 2013, she held Director positions in analytics at HealthNet, Blue Shield of California and North American Medical Management. Tiffany attended the University of California at San Diego and earned her B.A. in Economics. She received a Master of Public Health degree from California State University at San Diego.



Anastacia Swift, Executive Director of Human Resources

Anastacia Swift is the Executive Director of Human Resources at Alameda Alliance for Health (Alliance) with responsibilities for the overall administration, coordination, and evaluation of the Human Resources Department. In addition, she coordinates related activities with other Alliance departments and outside agencies.

By starting at the basic level of an HR assistant, and developing her education, practical knowledge, skills, and abilities, Anastacia built her career in human resources to become a versatile HR professional.  Before accepting her current position with the Alliance, Anastacia served as a consultant to the company’s Human Resources Department.  Her prior work experience consists of being an Employment and Employee Relations Manager with a San Joaquin Delta Community College, and the Total Compensation Manager with Alameda County Medical Center. Both of these positions required proficiency in employee supervision and training, knowledge of federal and state laws, and interactions with labor unions. Anastacia supports continuing education for HR professionals and has served as an adjunct instructor for private colleges.

Under Anastacia’s leadership, Delta College corrected deficiencies related to the college’s staff evaluation process, resulting in the Accrediting Commission of Community and Junior Colleges Western Association of Schools and Colleges, reporting the deficiencies as “completely satisfied.”

Anastacia is an active member of the Society for Human Resource Management (SHRM).  She has held a Professional HR (PHR) certification since 2003. An alumna of Holy Names University in Oakland, Anastacia holds a Bachelor of Arts degree in human resource management, and a Master’s degree in business administration, management and leadership, and organizational development.