The FARS/MCMIS Fatal Crash Record Matching Tool is designed to help reconcile differences between the Fatality Analysis Reporting System (FARS) and Motor Carrier Management Information System (MCMIS) databases. A methodology was developed to "match" fatal large truck and bus crash records between the FARS and MCMIS databases. The methodology defines a "matched record" between the two databases as a crash that involved at least one fatality, involved a large truck or bus, and contains the same information in several key fields (e.g., county, date, time, VIN, DOT #, etc.). The methodology has more than 40 unique matching combinations that can produce a single match between FARS and MCMIS fatal crash records.