
Primary Liability Required by FMCSA for motor carriers operating under their own authority. It is filed with the DOT and is mandatory for interstate for‑hire trucking.
Commercial Auto Liability Required for business‑owned vehicles that do not operate under FMCSA authority or are used for local, intrastate, or non‑for‑hire commercial purposes.
In short: Primary Liability protects the public under FMCSA authority. Commercial Auto Liability protects the public when a business‑owned vehicle causes damage, even if FMCSA filings are not required.

It covers bodily injury and property damage caused to others when your truck is involved in an accident.
Yes. If you operate a commercial vehicle, you must carry liability insurance to drive legally.
Most carriers and brokers require $1,000,000 in liability coverage.
No. Damage to your truck is covered under Physical Damage Insurance.
If you run under your own authority, yes — Primary Liability is your FMCSA‑filed liability coverage.
If you’re leased onto a carrier, the carrier may provide Primary Liability, but you still need Non‑Trucking Liability.