Workers' compensation records for residential contractors were combined with hours worked provided by the union to examine injury rates and costs among union carpenters between 1995 and 2000. Brief text descriptions were reviewed to describe more costly injuries. Costs per hour worked decreased over 6 years, largely because of declines in rates and mean costs for falls from elevations. Higher costs were associated with injuries from falls, raising framed walls, setting steel I-beams, and pneumatic nail guns. Prevention priorities should include fall protection; methods to safely set steel beams, raise and brace framed walls; and steps to prevent injuries from pneumatic tools. Cost data provide an important measure that is useful in focusing prevention; combined with even limited descriptions of injuries target areas for intervention can be identified based on frequency or severity.