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Excess casualty facilities

Marsh excess casualty facilities offer a single, streamlined block of insurance capacity designed to reduce claims fragmentation and harmonize contract language.
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In today’s complex claims environment, our excess casualty facilities — MX1, BX1, and MLOne — are designed to prevent claims from escalating into costly litigation and losses. Built on our proprietary follow‑form policy, Marsh XSellence, our facilities offer a single, streamlined block of capacity to reduce claims fragmentation, harmonize contract language across markets, and protect your balance sheet.

Today’s claims environment is marked by rising litigation costs and outsized jury awards known as nuclear verdicts, increasing the risk that a single large loss can cascade into severe financial and reputational harm.

Amid this complexity, some insurers have shifted from offering a few large placements to distributing capacity across many smaller blocks, so no single carrier faces an outsized impact. This fragmentation can complicate claims while also increasing administrative burden, creating inconsistent contract language between layers, and leaving coverage gaps that could result in costly claims for your organization.

Addressing a complex claims environment

Designed to prevent claim escalation, simplify complex insurance towers, and enable single blocks of large capacity, Marsh offers three excess casualty facility structures: MX1, BX1, and MLOne. These facilities can be deployed individually or used in conjunction with one another, further reducing the number of claims handlers.

In a claims landscape defined by greater volatility, our facilities aggregate and coordinate capacity across multiple markets. Streamlined excess casualty capacity can help you avoid claim escalation, close insurance gaps, and strengthen your insurance program overall. 

MX1

  • Aggregates excess capacity across markets into a single block with unified claims handling
  • 15+ markets and USD$150 million available limits
  • Enables fewer independent claims adjusters, aligned coverage, simplified negotiation, and less opportunity for plaintiff attorneys to exploit small limits

BX1

  • Bermuda domiciled version of the MX1 concept; a block of excess capacity accessed through Bermuda markets with the same unified claims approach
  • Five markets and USD$50 million available limits
  • Enables access to Bermuda markets in a single block, consistent contract language, and coordinated claims management

MLOne

  • Represents a further evolution of these solutions, aggregating significant excess capacity into a single lead umbrella block for stronger protection in litigious environments
  • Up to USD$30 million in lead umbrella capacity
  • Allows for a stronger barrier against aggressive claim strategies, preventing plaintiff attorneys from exploiting fragmented limits 

Benefits to you and the market

Marsh’s excess casualty facilities are mutually beneficial:

  • For your organization: We help deliver consistent terms across layers and coordinated claims handling, to reduce administrative friction, accelerate claim resolution, and better protect your balance sheet.
  • For the market: These facilities can minimize transaction complexity, reduce inter‑insurer disputes, and make it easier for specialty and alternative capital to participate, increasing potential available capacity and improving overall market efficiency and outcomes.

Why Marsh

Leveraging our Marsh XSellence excess casualty form, advanced analytics, and a team of 450+ specialized casualty professionals, we deliver competitive, tailored solutions that aim to address your unique needs.

Our centralized broking model and global network across 100+ countries enable us to spot market trends early and deliver coordinated, consistent service. Managing over $10 billion in premium and loss costs annually, we combine deep market experience and relationships to secure the optimal program structure, terms, and conditions to manage and mitigate your most urgent risks.

If you would like to learn more about the Marsh excess casualty facilities and how we can support you, please get in touch or contact your local Marsh advisor.

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