States with All-Payer Claims Databases (APCDs) have a long history of working to contain healthcare costs and improve health system performance using comprehensive, local, encounter-specific data. States are supporting the need for transparency in healthcare at the policy and consumer levels. States are documenting wide variations in costs and outcomes and targeting opportunities for interventions to reduce this variation. The examples below illustrate some of the ways APCD data are being used to promote transparency and oversight of healthcare utilization, quality, and costs.