The objective of the Los Angeles County, California (LAC), health care personnel (HCP) influenza vaccination improvement intervention was to increase HCP influenza vaccination coverage during the 2016-2017 influenza season via targeted outreach to LAC acute care hospitals. We selected 13 facilities for intervention and received tailored recommendations from a menu of evidence-based practices. Following the season, each hospital in the intervention group experienced a significant increase in vaccination coverage, which increased the LAC countywide average for all hospitals by 5%, from 74% to 79%.