Key takeaways:

• The U.S. E&S market nearly tripled direct written premiums between 2018 and 2024 and is the largest it has ever been. E&S outperformed the overall P&C market for growth, profit, and carrier financial strength as the risk landscape continued to evolve.
• Several factors, from continued risk pressures and changing carrier operating models, suggest that the E&S market will continue to comprise a significant portion of the P&C market, especially in commercial lines where it comprises over 25% of premiums in total, and over 35% in key lines.
• As the E&S market continues to mature, the need for credible, neutral data and analytically grounded insight is likely to increase to support profitability, growth, speed, and efficiency.

The U.S. excess and surplus (E&S) market has expanded rapidly over the past several years According to industry data, direct written premiums nearly tripled between 2018 and 2024, reaching $97.5B in U.S. written premiums by domestic writers¹. Indeed, data shows that E&S now represents about 25% of U.S. commercial lines premium excluding Lloyd’s and other non-U.S. domiciled insurers.² Stamping office data for 2025 shows continued double-digit transaction growth, with premium volume increasing at a more moderate pace in some lines and segments.³ Expectations are that premiums from domestic writers will have crested $100B in 2025, and will have reached over $130B when including Lloyd’s and other non-U.S. domiciled insurers.

What’s behind this growth and what does the future hold? In the past year, we’ve spoken with carriers and MGAs representing more than two-thirds of U.S. E&S direct written premium. Here are four key themes from those conversations.

More Risk Complexity Is an E&S Driver

Across major commercial lines, many indicate that certain risks have become more challenging to underwrite in standard admitted markets. Casualty remains pressured by social inflation, regulatory and litigation trends, and evolving exposures, particularly in habitational, construction, and hospitality classes. On the property side, many cite that extreme weather, cost inflation, and risk accumulation in exposed geographies can make loss outcomes more uncertain.

As these dynamics have contributed to strained standard markets, more business has moved to E&S, where carriers can often respond more quickly to evolving risks with greater flexibility in coverage and pricing. At a time of unprecedented growth and prominence, the E&S market has proven innovative and adaptable, with the participant group posting more favorable financial results compared to admitted ⁴.

E&S May No Longer Be a Temporary Release Valve

Historically, E&S expanded during periods of admitted market stress and contracted as conditions stabilized. The recent unprecedented stretch of E&S expansion suggests that this pattern has weakened for at least two reasons: structural shifts in risk and in how carriers operate.

Many report that the underlying risk pressures driving business into the E&S market appear tied to sustained trends. For example, while property shows signs of rate adequacy, and even early softening in certain segments, loss cost uncertainty, economic volatility, population growth in weather-exposed regions, and the potential for severe storm seasons can leave the market exposed to renewed disruption. Casualty, meanwhile, remains structurally challenged across a growing number of jurisdictions, leading to continued rate increases for many classes.

At the same time, the wholesale consolidation and innovation in flexible product and underwriting solutions, the expansion of dedicated E&S units within admitted carriers, and the scale and sophistication of MGAs and program administrators can be seen as reducing the historical “snap back” of business to admitted markets.

The Focus Is Shifting from Growth to Discipline

After several years of rapid expansion, the E&S market continues to grow. However, the overall growth is moderating with increasing differentiation across lines.

As a result, managing sustained high submission volumes and balancing underwriting speed with discipline are important as ever, with pricing accuracy and portfolio construction reportedly coming under greater scrutiny from capacity providers and management teams. The next phase of the E&S cycle may therefore not only focus on expansion for its own sake but on sustainability and profitability.

Data and Analytics Play a More Critical Role

Success in this complex and evolving market may increasingly favor carriers and MGAs that pair speed with technical underwriting and pricing discipline. E&S organizations are rapidly integrating data, analytics, and AI-enabled tools across underwriting and portfolio workflows to support more consistent decision-making at scale.

In this context, partners like Verisk play an important role. For example, our Core Lines E&S team works with carriers and MGAs to extend admitted market data and tools into non-admitted use cases, while also developing E&S specific data assets and insights that reflect how the market operates. The Core Lines E&S team’s focus is to serve as a long-term partner to a durable E&S market with credible datasets and analytically grounded insights for sustainable and profitable growth.

Ian Czaja

Ian Czaja is Head of Excess and Surplus for Verisk’s Core Lines Underwriting Solutions. He leads a team that is dedicated to the success of Verisk’s Core Lines E&S clients by helping them maximize the value of existing solutions while developing new E&S insights and tools. Prior to Verisk, Ian spent 15 years at Nationwide and The Hartford in strategy, transformation, and innovation roles. He held prior leadership positions in Management Consulting at The Boston Consulting Group, and in Engineering Product Development at Ford Motor Company.

Emma Brenner

Emma Brenner is a Core Lines Writer under Verisk’s Emerging Issues team. Emma came to Verisk after spending five years working in journalism and content development for a commercial insurance and risk management trade publication. At Verisk, Emma is responsible for authoring articles and other content to connect clients to the value of Core Lines products.