What Is Surplus Lines Insurance

What is surplus lines insurance? It is coverage placed with a non-admitted carrier when admitted carriers decline to cover the risk. The U.S. surplus lines market reached $115.4 billion in direct written premium in 2025, growing 58% from $73 billion in 2020 per WSIA 2025 data. Non-admitted carriers, also called excess and surplus (E&S) carriers, price and design policies with flexibility that admitted carriers cannot match. The trade-off: surplus lines policyholders receive no protection from state guaranty funds if their carrier becomes insolvent.

Key Takeaways

• The U.S. surplus lines market hit $115.4 billion in direct written premium in 2025 per WSIA 2025, a 58% increase from $73 billion in 2020
• Surplus lines carriers operate outside state rate-and-form filing requirements, giving them the flexibility to cover high-hazard, emerging, and unusual risks that admitted carriers cannot price
• State guaranty funds do not cover surplus lines policyholders: if a non-admitted carrier becomes insolvent, policyholders become general creditors, not fund beneficiaries
• A diligent search documenting admitted carrier declinations is a legal prerequisite in most states before any surplus lines placement can proceed
• Lloyd's of London syndicates write approximately 25-28% of all U.S. surplus lines premium, making Lloyd's the single largest participant in the E&S market
• Surplus lines now represent 11.2% of total U.S. property and casualty premium, up from 8.1% in 2019 per NAIC 2024 data

Why Surplus Lines Insurance Exists

Admitted carriers operate within tight regulatory constraints. They file rates with their state Department of Insurance, wait for approval, and then write policies only within those approved rate structures. This system works well for predictable, well-understood risks with sufficient loss history.

It breaks down in three situations.

Risks with no actuarial data. Cyber liability had almost no loss history before 2012. Admitted carriers could not file actuarially supported rates. Surplus lines carriers priced based on available exposure data and their own risk appetite, and built the cyber insurance market that now exceeds $15 billion annually per WSIA 2025.

Risks with catastrophic loss potential. Coastal property in Florida, Louisiana, and the Carolinas faces hurricane exposure that admitted carriers cannot profitably price at filed rates. Surplus lines carriers evaluate each property individually, accounting for construction quality, elevation, distance from coast, and building code compliance.

Risks with no standard classification code. A licensed cannabis dispensary, a commercial drone operator, a professional stunt team: these businesses fall outside any standard ISO classification. Admitted carriers have no filed rate. Surplus lines carriers design custom policies from scratch.

Surplus Lines vs. Admitted Insurance: Key Differences

The differences between admitted and surplus lines markets extend well beyond pricing flexibility.

Rate regulation. Admitted carriers submit rate filings to state DOIs and must charge within approved ranges. Non-admitted carriers set their own rate for each risk. This is why surplus lines premiums for similar risks can vary by 30-50% between carriers: each applies its own underwriting judgment without a regulatory floor or ceiling.

Form flexibility. Admitted carriers use state-approved policy forms. Non-admitted carriers design custom forms. This lets them tailor coverage to the risk, add exclusions that fit unusual operations, or build coverage structures that simply do not exist in any standard admitted form.

Guaranty fund protection. Every admitted carrier contributes to state guaranty funds. When an admitted carrier becomes insolvent, the fund pays claims up to state-specified limits, typically $300,000 to $500,000 per claim per NAIC 2024. Non-admitted carriers do not participate. A surplus lines carrier insolvency leaves policyholders as general unsecured creditors.

Distribution requirements. Any licensed agent or broker can sell admitted market policies. Surplus lines policies must flow through a licensed surplus lines broker, typically a wholesale broker. In most states, the retail agent cannot bind surplus lines coverage directly.

The Regulatory Framework: "Eligible Non-Admitted"

A common misconception: surplus lines carriers are not unlicensed. They hold a different status called "eligible non-admitted." Each state maintains an approved list of non-admitted carriers eligible to accept surplus lines business within that state.

To appear on an eligible carrier list, a surplus lines carrier must file financial statements with the state, maintain minimum capitalization levels, and typically hold an AM Best rating of B++ or better. Most states publish these lists publicly. The Florida Surplus Lines Service Office list, the California Surplus Line Association list, and the New York Excess Line Association list are the most commonly referenced.

This distinction matters for broker compliance. A surplus lines broker cannot legally place business with a carrier that does not appear on the state's eligible list, even if the carrier is financially strong. Placement with an ineligible carrier creates significant E&O exposure.

The Diligent Search Requirement

Most states require a "diligent search" before any surplus lines placement. The broker must approach admitted carriers, attempt to place the risk, and document each carrier's declination before the risk can legally be placed in the non-admitted market.

State requirements vary in specifics:

• Number of declinations required: Typically 2 to 3 documented declinations; Florida and some other states require 3 admitted carriers to decline
• What constitutes a declination: A written rejection, not merely a high quote or an unfavorable term; most state laws specify written documentation
• Timing: Most declinations come back within 24 to 72 hours via carrier portals, making the diligent search manageable within a standard quoting timeline
• Documentation retention: Most states require the broker to retain diligent search records for 3 to 5 years; some require filing with the stamping office

For risks where the coverage type is unavailable in the admitted market entirely, such as political risk insurance or kidnap and ransom, the diligent search documentation notes that no admitted carrier offers the product rather than documenting individual declinations.

The Guaranty Fund Gap: The Most Important Client Disclosure

The single most important disclosure in any surplus lines placement is the guaranty fund exclusion. Brokers must deliver a state-mandated surplus lines disclosure notice to the insured before or at the time of binding.

The practical consequences of this gap are significant.

A $2 million commercial property claim against an insolvent admitted carrier gets paid by the state guaranty fund up to the applicable limit (commonly $300,000-$500,000 per NAIC 2024 data). The remaining amount may be recovered from the carrier's estate over years.

The same claim against an insolvent surplus lines carrier goes entirely to the carrier's insolvency proceeding. The policyholder files as a general creditor and may recover cents on the dollar, or nothing, depending on the carrier's remaining assets.

This risk is manageable with proper carrier selection. Placing surplus lines coverage with AM Best A- rated or better carriers dramatically reduces insolvency risk. Most states require a minimum of B++ for eligible carrier status, but industry best practice is A- or better. The AM Best rating is the primary tool policyholders have in place of guaranty fund protection.

How a Surplus Lines Placement Works

A surplus lines placement follows a specific path through the distribution chain that differs from standard admitted placements.

Step 1: Risk identification. The retail broker receives the client's submission. They identify characteristics that signal a surplus lines risk: adverse loss history, high-hazard operations, catastrophe-exposed property, unusual business type, or limits exceeding admitted market capacity.

Step 2: Admitted market attempts. The broker approaches admitted carrier appointments, documents each approach, and collects written declinations. This is the diligent search. Electronic declinations through carrier portals satisfy the documentation requirement in most states.

Step 3: Submission to a wholesale broker. The retail broker sends the complete submission package to a wholesale broker who holds surplus lines licenses and relationships with non-admitted carriers. The package includes applications, 5 years of loss runs, financials for larger accounts, and any supplemental applications requested by specific E&S carriers.

Step 4: Wholesale broker markets the risk. The wholesale broker approaches non-admitted carriers based on their known appetite for the risk type. For a coastal Florida restaurant, the submission goes to Lloyd's syndicates specializing in Florida property and domestic surplus lines carriers with Florida exposure. For a cannabis dispensary, it goes to cannabis-specialty MGAs.

Step 5: Quote comparison and binding. Quotes return with varying terms, deductibles, and premiums. The retail broker presents options to the client with clear explanations of coverage differences. After client authorization, the wholesale broker binds coverage.

Step 6: Compliance and policy delivery. The wholesale broker handles surplus lines tax collection, stamping office filings (required in approximately 30 states), and diligent search documentation. The carrier issues the policy, the wholesale broker reviews it, and it flows to the retail broker for delivery to the insured with the required surplus lines disclosure notice.

AM Best Ratings and Carrier Selection

With no guaranty fund backstop, the carrier's AM Best Financial Strength Rating becomes the primary credit quality indicator for policyholders.

The AM Best rating scale for surplus lines carriers:

Lloyd's of London syndicates collectively carry an A (Excellent) AM Best rating per AM Best 2025. Lexington Insurance (AIG's surplus lines operation) holds an A rating. Markel's surplus lines operations hold an A- rating.

For a certificate of property insurance issued on a surplus lines policy, the carrier's AM Best rating may affect acceptance by lenders, general contractors, or project owners. Some construction contracts and loan agreements specify a minimum carrier rating in their insurance requirements.

Lines of Business Concentrated in the Surplus Lines Market

The surplus lines market is not evenly distributed across all coverage types. Specific lines concentrate in E&S because of their risk characteristics.

Property catastrophe. Approximately 40% of total E&S premium per WSIA 2025. Coastal property, wildfire-exposed property, and earthquake coverage. 65% of Florida coastal residential insurance now places in surplus lines following years of admitted carrier withdrawals.

Cyber liability. 40% of standalone cyber liability policies originate in the surplus lines market per WSIA 2025. Complex cyber programs with $10 million or more in limits, technology E&O combined with cyber, and first-party contingent business income for cloud service failures typically require E&S placement.

Professional liability for high-risk classes. D&O for early-stage companies, medical malpractice for high-risk specialties, and legal malpractice for high-exposure practice areas. Filed rates in the admitted market cannot accommodate the volatility in these classes.

Excess and umbrella casualty. High-capacity towers above $5 million to $10 million in total limits. Admitted carrier capacity at upper excess layers contracted significantly from 2019 to 2024, pushing a large portion of excess casualty placements into surplus lines.

Cannabis. Fewer than 10 admitted carriers write cannabis-related risks nationally per WSIA 2025. Surplus lines carriers, led by Lloyd's syndicates and specialty domestic E&S markets, provide the primary, excess, and specialty coverages the cannabis industry requires.

Habitational real estate. Five-plus unit residential apartment buildings with adverse loss history, older construction, or locations in jurisdictions with broad landlord liability exposure. Many admitted carriers restrict or exclude these risks.

Special events and entertainment. One-time events, concerts, festivals, and sports competitions. No operating history and unique risk profiles eliminate the admitted market as an option.

Top Surplus Lines Carriers in the U.S.

The surplus lines market concentrates among a relatively small number of major participants. Per WSIA 2025 and AM Best 2025 data:

• Lloyd's of London: approximately $27.7 billion in U.S. surplus lines premium (over 50 active syndicates)
• AIG (Lexington Insurance): approximately $9.8 billion
• Berkshire Hathaway specialty operations: approximately $7.2 billion
• Markel Corporation: approximately $5.4 billion
• Nationwide (Scottsdale Insurance): approximately $4.8 billion
• W.R. Berkley: approximately $4.5 billion
• AXIS Capital: approximately $3.1 billion
• Kinsale Capital Group: approximately $2.4 billion (fastest-growing domestic E&S carrier)

Lloyd's dominance reflects its syndicate structure. Over 50 competing syndicates, each with its own underwriting team and risk appetite, provide access to a broad range of surplus lines coverage within a single regulated market. A Lloyd's wholesale broker submission can simultaneously access syndicates specializing in property, casualty, professional liability, marine, and specialty lines.

FAQ

What is surplus lines insurance and when is it used?

Surplus lines insurance is coverage placed with a non-admitted carrier when admitted carriers decline to cover the risk. It is used when a risk is too hazardous for standard market classification, carries too much adverse loss history, sits in a catastrophe-exposed location, belongs to an emerging industry without filed rates, or requires limits beyond admitted carrier capacity. Per WSIA 2025, the market reached $115.4 billion in 2025 as placement needs in these categories grew consistently since 2020.

Is surplus lines insurance less safe than admitted coverage?

Surplus lines insurance is regulated, and most surplus lines carriers are financially strong. Two protections present in the admitted market are absent: state guaranty fund coverage and state-approved policy forms. A policyholders's protection against carrier insolvency comes entirely from the carrier's own financial strength. Brokers address this by placing with carriers rated A- or better by AM Best. Policy terms depend on the carrier's custom form, not a state-approved standard form, so careful review of coverage is required before binding.

What is the state guaranty fund and why doesn't it cover surplus lines?

State guaranty funds are funded by admitted carrier assessments. When an admitted carrier becomes insolvent, the fund pays covered claims up to state-specific limits, typically $300,000 to $500,000 per NAIC 2024. Surplus lines carriers do not pay into guaranty funds because they operate outside the admitted regulatory system. States created this structure intentionally: the surplus lines market exists for sophisticated commercial risks that accept non-standard terms in exchange for coverage availability. The policyholder must receive a written disclosure of the guaranty fund exclusion at or before policy binding.

What is a diligent search in surplus lines insurance?

A diligent search is the documented process of approaching admitted carriers and collecting their written declinations before placing a risk in the surplus lines market. Most states require 2 to 3 admitted carrier declinations with written documentation. Electronic declinations through carrier portals satisfy the requirement in most jurisdictions. The diligent search must be completed before binding, and records must be retained for 3 to 5 years depending on state requirements. Placement without a completed diligent search exposes the broker to regulatory penalties and E&O liability.

Who are the largest surplus lines carriers in the U.S.?

Per WSIA 2025 and AM Best 2025, the largest surplus lines carriers are Lloyd's of London at approximately $27.7 billion in U.S. surplus lines premium, followed by AIG (Lexington Insurance) at $9.8 billion, Berkshire Hathaway at $7.2 billion, Markel at $5.4 billion, and Nationwide (Scottsdale Insurance) at $4.8 billion. These five groups collectively write approximately 52% of U.S. surplus lines premium. Lloyd's unique syndicate structure gives it broad coverage across all surplus lines segments.

How has the surplus lines market grown in recent years?

The U.S. surplus lines market grew 58% from $73 billion in 2020 to $115.4 billion in 2025 per WSIA 2025. Annual growth rates ranged from 4.9% in the slowest year (2023) to 14% at the 2021 peak. The growth drivers were admitted market capacity withdrawals from catastrophe-exposed property in Florida and California, rapid expansion of cyber liability insurance, cannabis industry legalization creating new placement needs, and general hardening of admitted market conditions from 2019 to 2023. The surplus lines market share of total U.S. P&C premium grew from 8.1% in 2019 to 11.2% in 2025 per NAIC 2024.

BrokerageAudit's Submission Intake tracks diligent search documentation and E&S placement records for every account requiring surplus lines coverage. See how it works →

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