Primary Liability Insurance for Truckers: What It Covers and Why It Is Required

Primary liability insurance is the core coverage required for every carrier that operates commercial motor vehicles in interstate commerce. The Federal Motor Carrier Safety Administration (FMCSA) mandates it as a condition of operating authority, and no carrier can legally haul freight on public roads without it.

What Primary Liability Covers

Primary liability pays for bodily injury and property damage that your truck causes to third parties — other drivers, pedestrians, vehicles, or infrastructure — in an accident where your driver is at fault. It does not cover damage to your own truck, your own cargo, or injuries to your own driver.

FMCSA Minimum Requirements

The minimum required coverage depends on the type of freight you haul: - $750,000 for general freight (most dry van, flatbed, reefer) - $1,000,000 for oil transport and hazardous materials in smaller quantities - $5,000,000 for certain hazardous materials and explosive freight

Most insurers and brokers require at least $1 million in primary liability regardless of freight type, because $750,000 is considered inadequate for serious multi-vehicle accidents in today's litigation environment.

Filing the MCS-90

When your insurer issues a primary liability policy, they also file an MCS-90 endorsement with FMCSA. This document is the government's guarantee that your insurer will pay a valid claim even if your policy has lapsed or a coverage dispute exists. It is not a standalone policy — it is an endorsement that rides alongside your primary liability policy.

What Does Not Count as Primary Liability

Physical damage coverage is separate. So is cargo insurance. Bobtail insurance covers periods when you drive without a trailer. None of these satisfy the primary liability requirement. You need a specifically structured commercial auto liability policy with the MCS-90 filing attached.

Cost Factors

Premium for primary liability varies widely based on: - Years in business and safety history - Type of freight hauled - Operating radius and lanes - Driver experience and MVR records - Number of power units - Deductible selected

New authorities typically pay significantly more than established carriers with clean safety records. Expect first-year costs to be higher and to improve as your operating history builds.