12.3 Motor Carrier / Trucking and MCS-90

Key Takeaways

  • For-hire trucking is written on the Motor Carrier Coverage Form (CA 00 20) or older Truckers form (CA 00 12), adding trailer interchange, owner-operator, and non-trucking (bobtail) concepts.
  • FMCSA financial-responsibility minimums are $750,000 (non-hazardous), $1,000,000 (oil/certain hazardous), and $5,000,000 (most hazmat).
  • The BMC-91/91X is the filing with FMCSA proving minimum insurance exists; the MCS-90 is the policy endorsement guaranteeing public payment.
  • The MCS-90 protects the injured public, not the trucker: it pays final judgments up to the federal minimum even on unscheduled/excluded autos.
  • After an MCS-90 payment it otherwise would not owe, the insurer has a right of reimbursement against the insured; the MCS-90 never covers cargo or physical damage.
Last updated: June 2026

Why Trucking Needs Its Own Form

For-hire trucking risks transport other people's goods across state lines, so they face federal liability minimums and unique exposures (loading/unloading, trailer interchange, owner-operators). ISO publishes the Motor Carrier Coverage Form (CA 00 20) and the older Truckers Coverage Form (CA 00 12) for these accounts. The Motor Carrier form is now the standard; it added refinements for the modern logistics industry.

A motor carrier is a person or business that provides commercial transportation by auto. A private carrier hauls its own goods (a bakery's own delivery trucks) and may sometimes use the Business Auto form instead.

Trucking-Specific Symbols and Concepts

The Motor Carrier form keeps the symbol concept but adds trucking realities:

ConceptMeaning
Trailer interchangeLiability/physical damage for trailers of others in the insured's care under a written interchange agreement
Hired auto / owner-operatorCoverage for tractors leased from independent operators
Specified causes of lossCommon physical-damage choice for older rigs
Non-trucking use ('bobtail')Excludes use while not dispatched under the motor carrier's authority

Federal Filings: BMC-91 and the MCS-90

The Federal Motor Carrier Safety Administration (FMCSA) requires interstate for-hire carriers to prove financial responsibility. Two instruments matter:

  • The Form BMC-91 / BMC-91X is filed with the FMCSA as proof that liability insurance meeting the federal minimum exists.
  • The MCS-90 endorsement (the Motor Carrier Act endorsement) attaches to the auto liability policy and guarantees public payment.

Federal Minimum Limits

Cargo TypeMinimum Public Liability
Non-hazardous property (GVWR ≥ 10,001 lbs)$750,000
Oil / certain hazardous substances$1,000,000
Hazardous materials (most)$5,000,000

Worked point: A carrier hauling general freight in a 26,000-lb truck must carry at least $750,000 in public liability; a carrier of bulk gasoline must carry $1,000,000.

What the MCS-90 Actually Does

The MCS-90 is widely misunderstood. It is not coverage for the trucker — it is a suretyship/guarantee to the public. Under it the insurer agrees to pay any final judgment against the insured for public liability resulting from negligence, even if the policy itself would not cover the loss (for example, an unscheduled or excluded auto), up to the federal minimum.

Crucially, the insurer then has a right of reimbursement from the insured for any payment it would not have owed under the policy terms. So the MCS-90 protects the injured public, not the motor carrier's balance sheet.

Key MCS-90 Traps

  • It responds only to public liability — bodily injury and property damage to the public — not to the carrier's own cargo or physical damage.
  • It pays only up to the federal minimum ($750,000 / $1,000,000 / $5,000,000), not the policy's higher CSL.
  • It applies regardless of whether the auto involved is listed on the policy, which is why insurers seek reimbursement.
  • It is triggered by interstate or foreign commerce; purely intrastate hauls may fall under state filings instead.

Distinguishing the Filings

ItemPurpose
BMC-91 / 91XEvidence FILED with FMCSA that minimum insurance exists
MCS-90ENDORSEMENT on the policy guaranteeing public payment up to the minimum
Form E (state)State-level proof-of-insurance filing for intrastate authority

Exam summary: BMC-91 is the filing; the MCS-90 is the endorsement that makes the insurer pay the public even on a non-covered auto, with reimbursement rights against the insured.

Cargo and Trailer Interchange

Trucking accounts often add two coverages the auto form does not provide. Motor Truck Cargo insurance covers the carrier's legal liability for loss to the property of others being transported — the freight itself — which the BACF excludes under care, custody, or control. Trailer Interchange (endorsement CA 23 17) covers physical damage to trailers of others held under a written interchange agreement, a routine arrangement among interlining carriers.

Know the line: cargo coverage protects the goods; trailer interchange protects the borrowed trailer; the auto form protects the tractor and public liability. A single trucking program frequently stitches all three together.

Private versus For-Hire Carriers

A for-hire carrier transports others' goods for compensation and is squarely subject to FMCSA filings and the MCS-90. A private carrier hauls only its own goods incidental to its main business and may be written on the Business Auto form, though larger private fleets crossing state lines can still trigger federal financial-responsibility rules. Classifying the carrier correctly determines which form, filings, and minimum limits apply.

Test Your Knowledge

A trucker's tractor — accidentally left off the policy schedule — causes a serious injury accident in interstate commerce. The policy would normally deny because the auto is unscheduled. With an MCS-90 endorsement, what happens?

A
B
C
D
Test Your Knowledge

A motor carrier hauls bulk gasoline in interstate commerce. What is the minimum public liability limit required under FMCSA rules?

A
B
C
D

The MCS-90 Endorsement - Why It Is Not Really Insurance

The MCS-90 is a federally mandated endorsement on the auto policies of interstate motor carriers of property. It exists to guarantee that the public is paid for bodily injury or property damage even when the carrier's own policy would not respond.

FeatureMCS-90
PurposeGuarantee minimum financial responsibility to the public
Federal minimum$750,000 (general freight); higher for hazardous materials (up to $5,000,000)
Who is protectedInjured members of the public, not the insured
ReimbursementInsurer pays the public, then recovers from the insured any amount it would not otherwise owe

The critical exam point: the MCS-90 is a suretyship-style guarantee, not added coverage for the insured. If a loss falls outside the underlying policy (wrong vehicle, excluded operation) the insurer still pays the injured public up to the federal minimum, then seeks reimbursement from the motor carrier.

Exam Trap: Hazardous-materials and certain hazardous-substance haulers face the higher $5,000,000 filing requirement, while general property carriers must show $750,000. The MCS-90 does not lower a carrier's duty to buy adequate primary limits.