Prior to being elected to the state assembly, he was a pediatrician and professor at the UC Davis Children's Hospital, where he led the pediatric residency program. In 2005, CPT received the Community Campus Partnerships for Health Award and in 2008, Pan received the Campus Compact Thomas Ehrlich Faculty Award for Service Learning for his work on CHPT. Pan also taught community development at UC Davis. He is a board member of the United Way California Capitol Region, a past board member of BloodSource, a regional blood bank, and served for six years as a Commissioner on the Sacramento First 5 Commission, which supports programs for children 0–5 years. He was a founding board member and chair of Healthy Kids Healthy Future, a regional administrative agency that obtained health care coverage for over 65,000 children in Colusa, El Dorado, Placer, Sacramento, and Yuba counties. He also was a founding member of the Sacramento Health Improvement Project, a coalition of physicians, hospitals, clinics, and community activists working to strengthen the health care safety-net in Sacramento County.
Following , Pan and Senator Ben Allen introduced California Senate Bill 277 in 2015, which eliminated philosophical and religious beliefs exemptions to vaccine requirements for California school children. The bill passed and was signed into law by Governor Jerry Brown. Pan authored laws to expand newborn screening for severe combined immunodeficiency syndrome, adrenoleukodystrophy and all conditions recommended by the federal DHHS Recommended Universal Screening Panel. Pan authored legislation to extend the California Children's Services Program managed care carve-out and to establish the Medi-Cal Children's Health Advisory Board to guide Medi-Cal policy affecting children. In the California State Senate, Pan is Chair of the Committee on Health and the Committee on Budget and Fiscal Review Subcommittee #3 on Health and Human Services, the Select Committee on the 2020 United States Census, and the Select Committee on Asian Pacific Islander Affairs. He also serves on the Senate Committees on Budget and Fiscal Review; Business, Professions, and Economic Development; Education; Labor, Public Employment and Retirement and the Joint Legislative Budget Committee; Joint Legislative Committee on Emergency Management and Joint Committee on the Arts. Pan previously served as Chair of the Senate Committees on Public Employment and Retirement and Labor and Industrial Relations and on the Committee on Agriculture. Prior to serving in the state senate, he was a member of the California State Assembly. Pan was Chair of the Assembly Committee on Health, and was a member of the Committees on Agriculture, Appropriations, and Revenue and Taxation. Previously, Pan was Vice-Chair of the Assembly Veterans' Affairs Committee, and served on the Committees on Aging and Long-Term Care, and Accountability and Administrative Review. He was also the Chair of the Select Committee on Healthcare Workforce and Access to Care. He continues to practice at Wellspace Health's Oak Park Community Clinic, where he established the pediatric clinic while at UC Davis Children's Hospital.
Awards
Pan has received many awards for his community and professional leadership including the UC Davis Chancellor’s Award for Diversity and Community, the Medical Board of California Physician Humanitarian Award, the American Academy of PediatricsAbraham Jacobi Memorial Award for lifetime achievement in pediatrics, the Sierra Sacramento Valley Medical Society Medical Honor Award, the California School Nurses Organization Lydia Smiley Award, the United Way California Capitol Region Clarence La Rue Outstanding Volunteer Award, and the Child Abuse Prevention Council of Sacramento Hearts and Hands Award. Pan has also received numerous state and national awards for his legislative work including the National Consumers League Florence Kelley Consumer Leadership Award and the American Medical Association Nathan Davis Award for Outstanding Government Service.