In 1988, the Committee for the Study of the Future of Public Health identified the core functions of assessment, policy development, and assurance as key roles of the public health governmental sector. Some states have developed accreditation or performance assessment programs to measure how state and/or local government carry out these functions. Several of these programs share a common "on-site review" component defined as a site-specific visit to assess, observe, interview, review, evaluate, and/or survey a local/state agency or program regarding its ability to meet a set of public health standards. This article describes the experience of four states-Michigan, Missouri, North Carolina, and Washington-in developing and conducting on-site reviews for accreditation or performance assessment.