Primary liability insurance is the most legally critical coverage a commercial carrier can hold. It is federally mandated, required for operating authority, and the first line of financial defense when your truck causes injury or property damage to a third party. Yet many fleet owners misunderstand what it covers, what it doesn’t, and how to structure it correctly for their operation.
What Primary Liability Insurance Covers
Primary liability insurance covers bodily injury and property damage caused to third parties (other drivers, passengers, pedestrians, property owners) as a result of your truck’s operation. It does not cover:
- Damage to your own truck (that is physical damage coverage)
- Your own cargo (that is cargo insurance)
- Your own medical expenses (that is occupational accident or health insurance)
- Punitive damages in some states
FMCSA Minimum Liability Limits
Under 49 CFR Part 387, the federal minimum primary liability limits for for-hire carriers are:
- General freight (non-hazmat), vehicles under 10,001 lbs GVWR: $300,000
- General freight (non-hazmat), vehicles 10,001+ lbs GVWR: $750,000
- Hazardous materials (certain categories): $1,000,000
- Hazardous materials (highest risk categories, e.g., radioactive materials, explosives): $5,000,000
Most brokers and shippers require at least $1,000,000 in primary liability as a condition of tendering freight, making the federal minimum effectively a floor, not the market standard.
The MCS-90 Endorsement
The MCS-90 is a mandatory endorsement attached to your primary liability policy, required by FMCSA for all for-hire carriers. It is not additional coverage — it is a guarantee that your insurer will pay up to the required minimums even if the policy would otherwise not cover the claim (e.g., due to a policy exclusion), and then seek reimbursement from you. Understanding the MCS-90 is important: it protects the public, not the carrier, and can result in your insurer paying a claim and then suing you for repayment if the exclusion that triggered the MCS-90 was due to your own conduct.
Coverage for Leased Owner-Operators
When an owner-operator leases their truck to a carrier and operates under that carrier’s authority, the carrier’s primary liability policy must cover the leased vehicle while it is under dispatch. This is required by 49 CFR Part 376. The owner-operator’s own bobtail/NTL coverage fills the gap during off-dispatch periods.
About the Author
Sandra Kowalski is a commercial transportation finance specialist with 12 years of experience. → Back to the Commercial Truck Insurance & Finance Guide
Sources
- 49 CFR Part 387 — Minimum Levels of Financial Responsibility
- 49 CFR Part 376 — Lease and Interchange of Vehicles
- Insurance Information Institute
Disclaimer: This article is educational only. Insurance coverage and regulatory requirements vary by jurisdiction and specific policy terms. Always consult a licensed commercial insurance broker.