When introducing the DRG reimbursement system, the legislator constituted to conduct an impact evaluation focused on changes of (infra-)structures and quality of care within the inpatient sector as well as effects on other health care sectors. The G-DRG-Impact evaluation is divided into three research cycles referring to different phases of the G-DRG introduction. The evaluation of the first research cycle (introduction, years 2004 to 2006) has already been completed. A written report (pdf document, German version only) and the analyzed data (ACCESS database, German version only) are available on our homepage. Work on the second research cycle (convergence phase, years 2006 to 2008) is in progress and planned to be finished by December 2010.