Top Excess And Surplus Lines Carriers: What Insurance Agencies Must Know

The top excess and surplus lines carriers write approximately $83 billion of the E&S market's $98 billion total direct written premium, concentrating 85% of premium among the 25 largest carrier groups (AM Best 2025). Knowing which carriers lead in specific product lines, what AM Best ratings they hold, and how they distribute business determines how quickly and accurately your agency places hard-to-cover risks.

A submission routed to the right carrier through the right channel gets quoted in three days. The same submission sent through the wrong channel waits two weeks before a declination arrives. This explainer profiles the top excess and surplus lines carriers by segment, their appetite characteristics, and how agencies access each market.

Key Takeaways

• Lloyd's of London syndicates collectively write the largest share of U.S. E&S premium at approximately $18.2 billion in 2025, representing 18.6% of the total E&S market (AM Best 2025).
• AIG Lexington, Markel, and Scottsdale Insurance (Nationwide E&S) rank among the top three domestic E&S carrier groups, each writing more than $4 billion in annual U.S. E&S premium (AM Best 2025).
• All leading E&S carriers require wholesale broker access for retail agencies; direct appointments to E&S carriers are not available to retail producers without an E&S wholesale broker intermediary.
• The top wholesale broker intermediaries - RT Specialty, AmWINS, Burns & Wilcox, and CRC Group - collectively place over $35 billion in annual E&S premium and provide access to 300+ E&S carrier markets (WSIA 2025).
• Cyber E&S carriers At-Bay, Coalition, and Cowbell each grew premium over 40% annually from 2022 to 2025 by using real-time security scanning to underwrite risks admitted carriers decline (AM Best 2025).
• AM Best rates 92% of the top 25 E&S carrier groups at A- or better, indicating the surplus lines market's financial strength despite its non-admitted regulatory status (AM Best 2025).

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How the E&S Carrier Market Is Organized

The E&S carrier market operates in three tiers. The first tier consists of large-market carriers with broad product offerings and the capacity to write significant limits. The second tier is the wholesale broker intermediary layer that connects retail agencies to those carriers. The third tier is specialty E&S carriers focused on specific lines such as cyber, professional liability, or environmental.

Retail agencies do not access most E&S carriers directly. State insurance regulations require that surplus lines placements flow through a licensed surplus lines broker (also called a wholesale broker). The wholesale broker holds the surplus lines license, maintains carrier appointments, and submits business on the retail agency's behalf.

Understanding which carriers sit behind which wholesale brokers helps agencies choose the right distribution channel for each risk type.

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Segment 1: Large-Market E&S Carriers

These carriers write across multiple product lines, hold the highest capacity limits in the E&S market, and are accessible only through licensed wholesale brokers.

Lloyd's of London Syndicates

Lloyd's is not a single carrier but a marketplace of individual syndicates, each with distinct underwriting authority. The Lloyd's market collectively wrote approximately $18.2 billion in U.S. E&S premium in 2025, making it the single largest source of E&S capacity in the U.S. market (AM Best 2025).

Key appetite: Lloyd's syndicates specialize in property catastrophe (including windstorm, earthquake, and wildfire), marine cargo, aviation, political risk, terrorism, and specialty casualty lines that domestic carriers will not write. Individual syndicates include Beazley (specialty lines and cyber), Hiscox (professional lines and technology), and Atrium (property and marine).

AM Best rating: Lloyd's overall market holds an AM Best rating of A (Excellent). Individual syndicates are rated separately; agencies should verify the rating of the specific syndicate underwriting their placement.

Access: Retail agencies access Lloyd's exclusively through U.S. surplus lines brokers who hold Lloyd's coverholder or correspondent broker status. AmWINS, RT Specialty, and CRC Group all maintain significant Lloyd's access.

AIG Lexington Insurance Company

AIG Lexington is AIG's dedicated E&S subsidiary and one of the largest single E&S carrier entities in the domestic market. Lexington wrote approximately $7.4 billion in U.S. E&S premium in 2025 (AM Best 2025).

Key appetite: Lexington covers large commercial property (CAT and non-CAT), commercial GL for high-hazard industries, environmental liability, aviation, and high-value specialty risks including energy and marine. Lexington is particularly active in cat-exposed commercial property where admitted markets have withdrawn.

AM Best rating: A (Excellent), Stable outlook.

Access: Retail agencies access Lexington through wholesale brokers. Lexington maintains direct relationships with major wholesale intermediaries including RT Specialty, AmWINS, and CRC Group. Some accounts with premiums exceeding $500,000 may qualify for wholesale broker access to Lexington's brokerage division.

Markel Corporation

Markel operates E&S programs across property, casualty, and specialty lines with a focus on niche commercial segments. Markel wrote approximately $5.1 billion in E&S premium in 2025, with its E&S segment covering habitational property, general contractors, transportation, and professional liability (AM Best 2025).

Key appetite: Markel's E&S operations specialize in habitational property (apartments, condos, and HOAs), contractor and construction GL, transportation liability, and professional liability for architects and engineers. Markel's underwriting is known for flexibility on coverage terms for accounts that fit its niche program appetite.

AM Best rating: A (Excellent), Stable outlook.

Access: Retail agencies access Markel through wholesale brokers. Markel also operates a managing general underwriter (MGU) network that provides program access for agencies with significant volume in Markel's specialty segments.

Scottsdale Insurance Company (Nationwide E&S/Surplus Lines)

Scottsdale Insurance, Nationwide's E&S subsidiary, is one of the top domestic E&S premium writers with approximately $4.8 billion in annual E&S DWP (AM Best 2025). Scottsdale specializes in small to mid-market commercial accounts that fall outside admitted market appetite.

Key appetite: Scottsdale focuses on commercial property for habitational risks, GL for retail and service businesses, and specialty lines including liquor liability, vacant property, and small contractor accounts. Scottsdale's program business reaches into 25+ specialty niches through its managing general agent network.

AM Best rating: A+ (Superior), Stable outlook.

Access: Retail agencies access Scottsdale through wholesale brokers, but Scottsdale also distributes through appointed MGAs who provide direct access for retail agents in specific program lines.

Starr Companies

Starr operates a significant E&S platform with focus on commercial property, aviation, marine, and specialty casualty. Starr wrote approximately $4.2 billion in E&S premium in 2025 (AM Best 2025).

Key appetite: Starr's E&S operations cover large commercial and industrial property, workers compensation for high-hazard industries, accident and health, and aviation. Starr is particularly active in energy sector risks including oil and gas operations.

AM Best rating: A (Excellent), Stable outlook.

Access: Retail agencies access Starr through wholesale brokers. Starr also maintains direct relationships with large national brokers for accounts exceeding $1 million in premium.

Chubb's ACE American Insurance Company

Chubb uses ACE American as its E&S vehicle for placements that exceed admitted market appetite. ACE American wrote approximately $3.9 billion in E&S premium in 2025 (AM Best 2025).

Key appetite: ACE American focuses on high-value commercial property, excess casualty and umbrella for Fortune 500 and large middle-market accounts, environmental liability, and specialty lines including political risk and financial institutions bonds.

AM Best rating: A++ (Superior), Stable outlook.

Access: Retail agencies access ACE American through wholesale brokers for most placements. Large national accounts may access Chubb's brokerage division directly, but the E&S segment is wholesale broker distributed.

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Segment 2: Wholesale Broker Intermediaries

These are not carriers. They are the distribution layer that connects retail agencies to E&S carriers. Choosing the right wholesale broker determines which carrier markets your submissions reach.

Source: WSIA 2025 Annual Report.

RT Specialty

RT Specialty is among the largest wholesale brokers by E&S premium placed, with approximately $9.2 billion in annual volume and relationships with over 300 carrier markets (WSIA 2025). RT operates specialized divisions for property, casualty, professional lines, healthcare, and financial institutions.

Agencies working with RT Specialty gain access to Lloyd's syndicates, Lexington, Markel, Starr, and a range of specialty markets through a single wholesale broker relationship. RT's professional lines division has direct access to Beazley, AXIS Pro, and Philadelphia Insurance for management liability and errors and omissions placements.

AmWINS Group

AmWINS places approximately $8.7 billion in annual E&S premium across property, specialty casualty, and program business (WSIA 2025). AmWINS operates a large program business division that creates custom insurance programs for specific industries and distributes them through retail agents.

For agencies with volume in specialty niches such as healthcare, habitational real estate, or manufacturing, AmWINS program access can provide pre-negotiated coverage terms and pricing that individual placements cannot match.

Burns & Wilcox

Burns & Wilcox places approximately $6.1 billion annually with a distribution model that includes both a wholesale brokerage operation and direct MGA relationships (WSIA 2025). Burns & Wilcox is particularly strong in commercial property, personal lines E&S (including high-value homes), and professional lines.

For agencies with a mix of commercial and personal lines E&S needs, Burns & Wilcox's breadth makes it a practical single-relationship wholesale broker for small to mid-size agencies.

CRC Group

CRC Group places approximately $5.4 billion annually with a focus on casualty, construction, transportation, and agriculture (WSIA 2025). CRC's construction casualty division has direct access to Markel, Starr, and specialty construction markets that other wholesale brokers reach less efficiently.

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Segment 3: Specialty E&S Carriers by Line

These carriers focus on a single product category and write it with greater depth and breadth than generalist E&S carriers.

Cyber E&S Carriers

The cyber E&S market grew from $1.2 billion in 2020 to $6.8 billion in 2025 (AM Best 2025). Three carriers built market leadership through technology-enabled underwriting models.

At-Bay: At-Bay uses continuous security monitoring of insured businesses to price cyber risk more accurately than application-only underwriters. At-Bay wrote approximately $680 million in cyber premium in 2025 and holds an AM Best rating of A- (Excellent). Access: through wholesale brokers with cyber specialty practices, including RT Specialty and AmWINS cyber divisions.

Coalition: Coalition operates as both a cyber MGA and an insurance carrier in select states. Coalition's active monitoring platform scans insured businesses for vulnerabilities and alerts them before incidents occur. Coalition wrote approximately $590 million in cyber premium in 2025. AM Best rating: A- (Excellent). Access: Coalition distributes directly through appointed retail agents in addition to wholesale broker channels, making it more accessible than most E&S carriers.

Cowbell: Cowbell focuses on small to mid-size businesses with revenues under $100 million, a segment that larger cyber carriers often underwrite less efficiently. Cowbell wrote approximately $310 million in cyber premium in 2025. AM Best rating: A- (Excellent). Access: through appointed retail agents and wholesale broker channels.

Professional Liability E&S Carriers

AXIS Pro: AXIS Pro is the professional liability division of AXIS Capital, focusing on management liability, E&O for financial institutions, and technology professional liability. AXIS Pro wrote approximately $1.2 billion in professional lines E&S premium in 2025. AM Best rating: A (Excellent). Access: wholesale broker required.

Beazley: Beazley operates primarily through Lloyd's syndicates in the U.S. market and is one of the leading markets for media liability, miscellaneous professional liability, and cyber. Beazley wrote approximately $2.1 billion in U.S. professional and specialty lines in 2025. AM Best rating: A (Excellent) at the Lloyd's level. Access: through wholesale brokers with Lloyd's access.

Philadelphia Insurance Companies: Philadelphia focuses on nonprofit D&O, management liability for social services organizations, and professional liability for healthcare adjacent businesses. Philadelphia wrote approximately $950 million in professional lines E&S premium in 2025. AM Best rating: A++ (Superior). Access: through wholesale broker and some direct MGA relationships.

Environmental E&S Carriers

AIG Environmental Risk: AIG's environmental specialty unit writes pollution liability, contractor pollution, and PFAS-specific environmental coverage that admitted markets exclude. AIG Environmental Risk wrote approximately $1.4 billion in environmental E&S premium in 2025. AM Best rating: A (Excellent). Access: wholesale broker required.

Zurich Environmental: Zurich's environmental specialty unit focuses on large accounts with complex pollution exposures including manufacturing facilities, real estate remediation, and municipal landfill liability. Zurich Environmental wrote approximately $880 million in environmental E&S premium in 2025. AM Best rating: AA- (Superior). Access: wholesale broker required.

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Market Access Table: E&S Segments and Wholesale Broker Requirements

Source: WSIA 2025, AM Best 2025, individual carrier distribution guidelines.

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How to Choose the Right Wholesale Broker for Your Agency

Most retail agencies work with two to four wholesale brokers rather than one. Each wholesale broker has distinctive carrier relationships and underwriting appetites that favor different risk types.

The selection process has three steps. First, identify which E&S lines represent the largest volume in your book or the fastest growth opportunity. Second, research which wholesale brokers have the strongest carrier access in those specific lines. Third, contact the wholesale broker's retail agency development team to understand their submission requirements, turnaround commitments, and commission structures before placing business.

Agencies that spread E&S volume across too many wholesale brokers reduce their relationship value at each one. AM Best 2025 research shows that agencies concentrating at least 60% of their E&S volume with two or three primary wholesale brokers receive faster turnaround, better underwriting attention, and more favorable terms than agencies distributing volume broadly.

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Frequently Asked Questions

Q: Who are the top excess and surplus lines carriers by premium volume in 2025?

By total U.S. E&S direct written premium, the leading carrier groups in 2025 are: Lloyd's of London syndicates collectively ($18.2 billion), AIG Lexington ($7.4 billion), Markel ($5.1 billion), Scottsdale/Nationwide E&S ($4.8 billion), Starr Companies ($4.2 billion), and ACE American/Chubb E&S ($3.9 billion) (AM Best 2025). These six groups account for approximately $43.6 billion, or 44.5% of the total E&S market.

Q: Can retail insurance agencies get direct appointments with top excess and surplus lines carriers?

Most top E&S carriers do not offer direct appointments to retail agencies. Surplus lines regulations in most states require that retail agents work through a licensed surplus lines broker (wholesale broker) to place business with non-admitted carriers. A small number of E&S carriers, including Coalition and Cowbell in cyber, offer direct retail agent appointments for specific products. Most placements require a wholesale broker intermediary (NAIC 2025).

Q: What AM Best ratings do the top excess and surplus lines carriers hold?

AM Best 2025 data shows that 92% of the top 25 E&S carrier groups hold AM Best ratings of A- (Excellent) or better. Notable ratings: ACE American and Philadelphia Insurance hold A++ (Superior); Scottsdale/Nationwide holds A+ (Superior); AIG Lexington, Markel, Starr, AXIS Pro, and Beazley at the Lloyd's level hold A (Excellent). AM Best ratings for E&S carriers are important because surplus lines policies are not backed by state guaranty funds.

Q: How do wholesale brokers differ from excess and surplus lines carriers?

Wholesale brokers are distribution intermediaries, not carriers. They do not underwrite or bear insurance risk. Wholesale brokers hold surplus lines licenses, maintain carrier appointments, and submit business from retail agencies to E&S carriers on a commission basis. E&S carriers are the actual underwriters who accept risk and pay claims. RT Specialty, AmWINS, Burns & Wilcox, and CRC Group are wholesale brokers; Lloyd's, AIG Lexington, and Markel are carriers (WSIA 2025).

Q: What submission information do top E&S carriers typically require?

Submission requirements vary by carrier and line, but common requirements across top E&S carriers include: five years of prior loss runs, current and expiring policy declarations, a detailed description of operations, revenue or sales data, prior carrier and expiration date, and any relevant supplemental applications for specialty lines. For property, carriers typically require a recent appraisal or replacement cost estimate. For professional liability, carriers require a claims history narrative for any losses exceeding $50,000. Incomplete submissions are the primary cause of delayed quotes (WSIA 2025).

Q: How do E&S carrier AM Best ratings matter if surplus lines policies lack guaranty fund protection?

State guaranty funds protect policyholders when admitted carriers become insolvent, but they do not cover surplus lines policies. This makes AM Best ratings more important in E&S placements than in admitted market placements. If an E&S carrier becomes insolvent, the policyholder's only recourse is the carrier's assets in receivership, with no state fund backstop. Agencies placing business with E&S carriers rated below A- by AM Best take on significant reputational and E&O exposure. Most professional agency standards recommend placing E&S business only with carriers rated A- or better (AM Best 2025).

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Take the Next Step

Getting submissions to the right E&S carrier starts with capturing the right information at intake. See how BrokerageAudit's submission intake tool organizes E&S account data so your wholesale broker relationships get complete packages from day one.

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Written by Javier Sanz, Founder of BrokerageAudit. Last updated April 2026.