This report describes the similarities and differences between the National Crime Victimization Survey (NCVS), sponsored by BJS, and the FBI’s National Incident-Based Reporting System (NIBRS). The NCVS and NIBRS measure a set of crime offenses that overlap but are not identical, which leads to differences in estimates between the two data sources. The NCVS interviews victims on crimes both reported and not reported to police, while NIBRS collects data on crime recorded by law enforcement agencies. Taken together, these two measures of crime provide a more comprehensive picture of crime in the United States. The publication includes statistical estimates from both data sources; both show that the rate of violent crime in 2021 was not statistically different from the rate in 2020.