AHRQ has revised online tutorials that help researchers and others use the agency’s Healthcare Cost and Utilization Project (HCUP). HCUP, the nation’s most comprehensive source of hospital data, includes national and state data on inpatient care, ambulatory care and emergency department visits. The updated HCUP Overview Course provides information about the sources of HCUP data, features of the database, software tools and products. Additional tutorials instruct users on how to calculate standard errors and how to load and check HCUP data. Contact HCUP User Support for questions about the HCUP Online Tutorial Series.