12.3 Motor Carrier / Trucking and MCS-90

Key Takeaways

  • The Motor Carrier Coverage Form (ISO CA 00 12) suits both for-hire and private carriers and incorporates trailer-interchange handling.
  • Trailer interchange covers the insured's legal liability for physical damage to NON-OWNED trailers held under a written interchange agreement.
  • The MCS-90 is a federal financial-responsibility endorsement that guarantees payment to the injured public, even for otherwise-excluded losses.
  • FMCSA public-liability minimums are $750,000 (non-hazardous), $1,000,000 (oil/certain hazardous), and $5,000,000 (hazardous materials/explosives).
  • Cargo is never insured by liability or the MCS-90 - motor truck cargo coverage is required for freight.
Last updated: June 2026

Trucking and Motor Carrier Forms

Long-haul and for-hire trucking risks need specialized forms because they swap trailers, cross state lines, and must satisfy federal filings. The original ISO form was the Truckers Coverage Form. The Motor Carrier Coverage Form (CA 00 12) is now the common choice because it fits both private and for-hire carriers and folds in trailer-interchange handling.

A motor carrier is a business that transports property by auto in commerce. A for-hire carrier hauls others' goods for pay; a private carrier hauls its own goods. Both can be written on CA 00 12.

FeatureTrucking FormsStandard Business Auto
Target marketFor-hire and private carriersGeneral commercial
Trailer interchangeBuilt-inNot addressed
MCS-90 / federal filingsYesGenerally no
CargoEndorsement/separateSeparate policy

Trailer Interchange

Carriers exchange trailers under written interchange agreements so loaded trailers move continuously between carriers. Trailer interchange coverage insures the insured's legal liability for physical damage to a non-owned trailer in its possession under such an agreement.

The coverage can be written on a comprehensive, specified causes of loss, or collision basis, each with its own limit and deductible.

Exam trap: trailer interchange applies only to non-owned trailers under a written agreement. The insured's owned trailers are covered as autos, not under trailer interchange. There must be a written interchange agreement for the coverage to respond.

Federal Financial Responsibility - the MCS-90

Interstate for-hire carriers must prove financial responsibility under 49 CFR Part 387 of the Federal Motor Carrier Safety Administration (FMCSA) rules. The MCS-90 endorsement attaches to the auto liability policy and acts as a surety-like guarantee: the insurer will pay a final judgment to a member of the injured public even if the specific loss would otherwise be excluded or uninsured under the policy.

Crucially, the MCS-90 protects the public, not the insured. When the insurer pays a claim that the policy itself would not have covered, the insurer may seek reimbursement from the insured.

Cargo HauledFMCSA Minimum Public Liability
Non-hazardous property (most freight)$750,000
Oil / certain hazardous substances$1,000,000
Hazardous materials / explosives$5,000,000

Trucking, MCS-90, and Federal Filing Traps

Trucking risks are written on the Motor Carrier Coverage Form (CA 00 20) or the older Truckers form, because federal law imposes financial-responsibility minimums on motor carriers that the standard Business Auto Form does not satisfy. The most tested concept is the MCS-90 endorsement, a federally mandated attachment that guarantees the public will be paid for BI/PD/environmental damage even if the policy would otherwise not cover the loss.

ElementDetail
MCS-90 purposeEnsures public is paid up to federal minimums
Minimum limitsVary by cargo: e.g., $750,000 (general freight) to $5,000,000 (certain hazmat)
Carrier's obligationInsurer pays the public, then recovers from the insured if no coverage existed
Trip vs. specified-auto basisDifferent ways to schedule covered trucks

A critical exam point: the MCS-90 is not coverage for the insured — it is a surety-like guarantee to the public. If the insurer pays a claim only because of the MCS-90 (a claim the policy itself excluded), the insurer has a right of reimbursement against the trucker.

Worked scenario: A trucker hauling hazmat causes an accident injuring the public, but the specific tractor was not listed on the policy (an excluded auto). The policy would normally deny, yet the MCS-90 forces the insurer to pay the injured public up to the federal minimum (here $5,000,000 for the hazmat class), after which the insurer bills the trucker for the amount paid. This "pay-the-public-then-recover" mechanism is the single most tested motor-carrier concept.

Test Your Knowledge

An interstate carrier hauling ordinary non-hazardous freight must carry what minimum public-liability limit under FMCSA rules, as evidenced by the MCS-90?

A
B
C
D

Filings and the Cargo Gap

The BMC-91 / BMC-91X is the FMCSA filing that evidences public-liability coverage; a surety bond on form BMC-85 is an alternative. BMC-34 / BMC-83 relate to cargo filings for household-goods and certain carriers.

The cargo gap

Neither liability, the MCS-90, nor any of the above insures the freight the carrier is hauling for others. Motor truck cargo coverage is an inland marine line that insures the carrier's legal liability for loss to the property of others in transit. It is rated by commodity and limit per vehicle and is often required by shippers before a load is tendered.

Intrastate carriers follow state minimums, which can differ from the federal $750K/$1M/$5M tiers - watch the stem for whether the route crosses state lines.

Test Your Knowledge

Trailer interchange coverage on the Motor Carrier Coverage Form responds to which of the following?

A
B
C
D

Who Is an Insured on the Motor Carrier Form

The Motor Carrier Coverage Form modifies the standard insured definition to address the realities of trucking. The named insured is covered for any covered auto. Anyone using a covered auto the named insured owns, hires, or borrows with permission is an insured.

A frequent exam point involves the trucker-shipper relationship. When a carrier leases its rig to a motor carrier under a lease (a leased-operator arrangement), who is the insured can hinge on the lease terms and trip-lease endorsements. A lessor (the owner-operator) and a lessee (the motor carrier) may each need to appear as an insured so the public is protected no matter whose name is on the door.

Anyone liable for the conduct of an insured is covered to the extent of that liability - the same vicarious-liability principle as the standard Business Auto form.

Bobtail and Non-Trucking Use

A driver operating a tractor without a trailer and not under dispatch - for example, driving home after dropping a load - creates a coverage question the exam likes to test. While the rig is leased to a motor carrier, the carrier's policy typically covers operations in the business of the carrier; personal use is excluded.

TermMeaning
BobtailTractor operated without a trailer attached
DeadheadDriving with an empty trailer, no revenue load
Non-trucking use (bobtail) liabilityCovers the owner-operator when NOT under dispatch

Non-trucking use (NTU) / bobtail liability is purchased by the owner-operator to fill the gap when the tractor is used outside the motor carrier's business. The exam pairs this with the principle that the motor carrier's policy covers in-business use, leaving personal use to the owner-operator's NTU coverage.