---
title: Commercial motor vehicle (CMV)
description: A vehicle defined in 49 CFR 390.5 that triggers FMCSA safety and qualification rules.
date: 2026-10-20
lastReviewed: 2026-10-23
canonical: /glossary/commercial-motor-vehicle
---
A **commercial motor vehicle (CMV)** is defined in [49 CFR 390.5](https://www.ecfr.gov/current/title-49/section-390.5). Part 391 driver qualification rules apply when a person drives a CMV for a motor carrier, subject to exceptions in subpart G.