Despite record-high immunization coverage nationally, there is considerable variation across state and local immunization programs, which are responsible for the implementation of vaccine recommendations in their jurisdictions. The objectives of this study were to describe activities of state and local immunization programs that sustained high coverage levels across several years and to identify common themes and practical examples for sustaining childhood vaccination coverage rates that could be applied elsewhere. We conducted 95 semi-structured key informant interviews with internal staff members and external partners at the 10 immunization programs with the highest sustained childhood immunization coverage from 2000 to 2005, as measured by the National Immunization Survey. Interview transcripts were analyzed qualitatively using a general inductive approach. Common themes across the 10 programs included maintaining a strong program infrastructure, using available data to drive planning and decision making, a commitment to building and sustaining relationships, and a focus on education and communication. Given the challenges of an increasingly complex immunization system, the lessons learned from these programs may help inform others who are working to improve childhood immunization delivery and coverage in their own programs.