Glossary
What is an MCS-90?
An MCS-90 is a federal endorsement attached to a motor carrier's liability insurance policy that guarantees the insurer will pay valid public claims up to FMCSA's minimum financial-responsibility limits — $750,000 for general freight, and $1,000,000 or $5,000,000 for certain hazardous materials. It is a public-protection backstop required for federal operating authority, not additional coverage the carrier buys for itself.
By the XDate Alert team — built on public FMCSA / MOTUS records and federal regulations, reviewed against primary sources.
Last updated .
What the MCS-90 actually does
The MCS-90 sits on top of a carrier’s liability policy and changes how that policy behaves toward the public. Normally an insurer can deny a claim that falls under a policy exclusion. The MCS-90 removes that option for the federal minimum: if a member of the public wins a valid claim arising from the carrier’s operations, the insurer must pay up to the required minimum even if the underlying policy would not have responded. The insurer can then seek reimbursement from the carrier. In effect, it guarantees there is money behind every authorized motor carrier on the road, up to the federal floor.
MCS-90 vs the policy vs the filing
Three things are easy to confuse. The policy is the insurance contract. The MCS-90 is an endorsement to that policy guaranteeing the federal minimums. The BMC-91 or BMC-91X is the filing the insurer submits to FMCSA as proof the coverage exists. A carrier needs all three aligned to hold operating authority: a real policy, the MCS-90 endorsement meeting the right minimum, and the filing on record with FMCSA.
The minimum amounts (49 CFR §387.9)
- $750,000 — general freight (non-hazardous).
- $1,000,000 — certain oil and listed hazardous materials.
- $5,000,000 — large quantities of the most dangerous hazardous materials.
Passenger carriers carry their own minimums based on seating capacity. The MCS-90 guarantees the carrier meets whichever threshold its operation requires.
Why it matters when coverage changes
The MCS-90 only protects the public while a compliant policy is on file. When an insurer files a cancellation, the carrier’s federal coverage is on a countdown — and any replacement must itself include the MCS-90 and be filed before the cancellation date. For an agent, that makes the endorsement part of the standard replacement package. See what happens if coverage lapses or learn what operating authority is.
Sources
Frequently asked questions
What is an MCS-90 in simple terms?
The MCS-90 is a federal endorsement attached to a motor carrier's liability policy. It promises FMCSA and the public that, regardless of the policy's own terms, the insurer will pay valid claims up to the federal minimum limits. It is a public-protection backstop, not extra coverage the carrier buys for itself.
How is the MCS-90 different from the insurance policy?
The policy is the contract between the carrier and insurer; the MCS-90 is an endorsement that overrides the policy's exclusions for the purpose of meeting federal financial-responsibility rules. If the policy would not pay a covered judgment, the MCS-90 still requires the insurer to pay the public claimant up to the federal minimum, then seek reimbursement from the carrier.
What are the MCS-90 minimum amounts?
Under 49 CFR §387.9, the minimums are $750,000 for general freight, $1,000,000 or $5,000,000 for certain hazardous materials depending on type and quantity, and separate minimums for passenger carriers. The MCS-90 guarantees the carrier meets whichever applies.
Why do insurance agents care about the MCS-90?
Because it is part of the federal filing package that keeps a carrier legal. When a carrier's coverage is cancelled, the agent replacing it must put a compliant policy — with the MCS-90 and the BMC-91/BMC-91X filing — back on file before the cancellation date, or the carrier loses authority.