Primary liability is the policy that makes you legal. It's the biggest line item on your insurance bill, the one FMCSA requires, and the one brokers ask about first. Here's what it actually does, and just as important, what it doesn't.

What primary liability covers

Primary auto liability pays for the harm your truck does to other people. Two buckets:

  • Bodily injury: medical bills, lost wages, pain and suffering for people injured in an accident you caused. This is where the big numbers live.
  • Property damage: the car you hit, the guardrail, the building, the load on someone else's truck, the cleanup.

It also pays for something people forget until they need it: defense costs. When you get sued (and after a serious accident, you will), your insurer hires and pays the lawyers. In trucking litigation, defense alone can run six figures, and it's covered on top of, or within, your limit depending on the policy.

The key mental model: liability coverage protects your assets and your business from claims by others. It is not coverage for your stuff.

The federal minimums: the $750k vs. $1M reality

For most for-hire carriers hauling general freight in interstate commerce, the federal minimum is $750,000 in liability coverage. Hazmat haulers face much higher requirements, up to $5,000,000 depending on the materials.

So why does virtually every policy get written at $1,000,000? Because the market decided $750k isn't enough:

  • Brokers and shippers require $1M. Nearly every broker packet you'll ever sign specifies $1M primary liability. Run at the federal minimum and you're legal, but you can't get loaded.
  • Insurers are geared for it. The $1M CSL (combined single limit) policy is the standard product; quoting $750k rarely saves what you'd expect.
  • Verdicts have outgrown both numbers. Serious injury cases routinely exceed $1M, which is why larger fleets buy excess/umbrella layers on top.

Practical translation: treat $1M as the real minimum for a working carrier.

The MCS-90: not what most people think

Attached to your policy is an endorsement called the MCS-90. Truckers often assume it's extra coverage for them. It isn't. The MCS-90 is a promise to the public, required by federal law: it guarantees that a member of the public injured by your operations gets paid up to the federal minimum, even if the policy would otherwise deny the claim: wrong truck listed, coverage lapse in some scenario the policy excludes.

Here's the sting: when the MCS-90 pays a claim the underlying policy didn't actually cover, the insurer has the right to come after you for reimbursement. So the MCS-90 protects the injured public, not you. Your real protection is the policy itself, which is why keeping your equipment schedule, drivers, and operations accurately reported matters so much.

What primary liability does NOT cover

This list surprises people constantly:

  • Your truck and trailer. That's physical damage coverage, sold separately.
  • The freight you're hauling. That's motor truck cargo.
  • Your own injuries. That's medical payments coverage, PIP, or workers' comp/occupational accident depending on your setup.
  • Driving outside the business without a trailer or dispatch. Depending on how you operate, that's where non-trucking liability comes in.
  • General business liability. Someone slipping in your shop or office needs general liability, a different policy.

If your entire insurance program is one primary liability policy, you're legal, and everything you own is uninsured.

How limits actually work

Most trucking liability policies are written as a combined single limit (CSL): one pot of money, commonly $1,000,000, covering bodily injury and property damage together per occurrence. One bad accident with three injured people and two totaled cars all draws from the same pot.

Things to understand about that pot:

  • It's per occurrence, and it's finite. Once the limit pays out, anything beyond it is on you.
  • Defense costs may erode the limit or sit outside it. Ask which way your policy works, because it changes how much is actually available for the claim.
  • Deductibles on liability are uncommon for small carriers. This coverage generally pays from dollar one.

Why brokers require the limits they do

Brokers require $1M (and sometimes more for specific freight) for a simple reason: when your insurance runs out, plaintiffs' lawyers look up the chain: at the broker and the shipper. Requiring solid limits from every carrier is how brokers protect themselves. It's also why they verify coverage through certificates and monitoring services, and why a lapse can get you removed from a broker's carrier list overnight.

It's not personal. It's just where the liability flows.

How McClure helps

Primary liability pricing swings widely between carriers based on your radius, cargo, drivers, and safety scores, which is exactly why we're independent. We shop your risk across multiple markets, make your federal filings so your authority activates on time, and make sure the policy actually matches how you operate, because a mismatch is how MCS-90 reimbursement nightmares start. If you're not sure what your current policy really covers, send it over. We read these for a living.