The economic recession that began in California in 2008 did not affect all counties equally. Using data from several years of the California Health Interview Survey, this policy brief examines the differences between 2007 and 2009 for the populations who were uninsured "for all or part of the prior year." During this time period, counties with high unemployment and lower household income saw the highest growth in the uninsured population, due to a large drop in job-based coverage and only a small increase in public coverage. Compared to the uninsured population in California in 2007, Californians who were uninsured for all or part of 2009 were older, more likely to be U.S.-born citizens, had lower household incomes, and were more likely to be unemployed and looking for work.