What primary liability covers
If one of your trucks is at fault in a crash, primary auto liability pays the other side's medical bills, vehicle repairs, property damage and legal defense, up to the policy limit. It does not pay for your own equipment or freight; those need physical damage and cargo coverage.
Federal minimum limits
FMCSA sets minimum liability limits in 49 CFR Part 387:
| Type of operation | Minimum limit |
|---|---|
| General freight, vehicle 10,001 lbs or more | $750,000 |
| General freight, vehicle under 10,001 lbs | $300,000 |
| Oil and certain hazardous materials | $1,000,000 |
| Hazmat in bulk and other high-risk materials | $5,000,000 |
Filings and endorsements
Your insurer files proof of coverage with FMCSA on Form BMC-91 or BMC-91X, and interstate policies carry the MCS-90 endorsement, which guarantees the public is paid up to the federal minimum. If a policy cancels, FMCSA is notified, so coverage gaps can put your authority at risk.
What drives a fleet's liability premium
- Crash history and loss runs for the last three to five years
- CSA BASIC percentiles, especially Unsafe Driving, HOS and Crash Indicator
- Driver quality: ages, experience, MVRs and turnover
- Radius, lanes, states and commodities
- Safety program, cameras and telematics
Liability is usually the largest part of a fleet's premium, and it's the part most influenced by safety and compliance. That's where we focus.
Last updated November 10, 2026. Reviewed by a licensed insurance professional at Haul Good Insurance.