The Kaiser Permanente Northern California (KPNC) Member Health Survey (MHS) is used to describe sociodemographic and health-related characteristics of the adult membership of this large, integrated health care delivery system to monitor trends over time, identify health disparities, and conduct research. To provide an overview of the KPNC MHS and share findings that illustrate how survey statistics and data have been and can be used for research and programmatic purposes. The MHS is a large-scale, institutional review board-approved survey of English-speaking KPNC adult members. The confidential survey has been conducted by mail triennially starting in 1993 with independent age-sex and geographically stratified random samples, with an option for online completion starting in 2005. The full survey sample and survey data are linkable at the individual level to Health Plan and geocoded data. Respondents are assigned weighting factors for their survey year and additional weighting factors for analysis of pooled survey data. Statistics from the 1999, 2002, 2005, 2008, and 2011 surveys show trends in sociodemographic and health-related characteristics and access to the Internet and e-mail for the adult membership aged 25 to 79 years and for 6 age-sex subgroups. Pooled data from the 2008 and 2011 surveys show many significant differences in these characteristics across the 5 largest race/ethnic groups in KPNC (non-Hispanic whites, blacks, Latinos, Filipinos, and Chinese). The KPNC MHS has yielded unique insights and provides an opportunity for researchers and public health organizations outside of KPNC to leverage our survey-generated statistics and collaborate on epidemiologic and health services research studies.