Glossary · updated October 30, 2026
Power Unit
Also known as: CMV, Commercial Motor Vehicle
By Korey Sharp-Paar · Reviewed by the Fast Trucking Compliance team
Definition
A power unit is a self-propelled commercial motor vehicle - a truck or truck-tractor - used to transport property or passengers in commerce. UCR fee brackets count power units, not trailers or towed equipment. The figure normally comes straight from the power-unit total a carrier reports to the FMCSA on Form MCS-150, which is why an out-of-date MCS-150 can throw off a UCR filing. Carriers may exclude vehicles used exclusively in intrastate commerce. The power-unit count places the carrier in one of six UCR brackets, from 0–2 vehicles at the bottom to 1,001 or more at the top.
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How to Count Your UCR FleetUCR counts self-propelled power units only - never trailers. Count vehicles at 10,001 lbs GVWR or more per 49 USC §31101, using your MCS-150 or the June 30 actual count.
Related terms
- UCR Vehicle Count(CMV Count)
- MCS-150(Motor Carrier Identification Report)
- UCR Fleet-Size Brackets(Fleet-Size Brackets)