Penomic ResearchInsurance · October 2026

Underwriting appetite is institutional knowledge

AI now reads and triages submissions in seconds, but the appetite that decides what a carrier writes, on what terms and with which referrals still lives in senior underwriters' heads. In a softening market, with regulators asking for the record, that gap decides results.

By Jared D. Yerian and Jennifer Kilian · 17 minute read

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Ask a chief underwriting officer what the company's appetite is and the written answer takes a page. The real answer takes an afternoon, most of it exceptions: the sprinkler configuration the head of property will not accept at any price, the broker whose book has earned a stretched limit, the referral approved in March that has quietly become the rule. That is the appetite. It determines the loss ratio more than any model does, and almost none of it exists in a form a system, a new hire or a delegated partner can apply.

The 2026 market has made that a financial problem. Marsh's Global Insurance Market Index fell 6 percent in the second quarter, the eighth consecutive quarterly decline, with global property rates down 12 percent and only casualty still rising, by 2 percent.1 At Lloyd's, rates fell 6.7 percent in the first half, and Patrick Tiernan told the market in September: "We are currently turning away more new business than we accept."2 Swiss Re Institute expects global non-life premiums to grow 0.6 percent in real terms this year against a trend of 3.6 percent, and projects non-life return on equity falling from a 14 percent peak in 2025 to 11.4 percent in 2026 and 7.7 percent by 2028 if the softening continues (Exhibit 1).3 AM Best puts the US property and casualty combined ratio at 95.0 for 2025 and expects one "a couple points higher in 2026."4 Catastrophe losses offer a reprieve rather than a reset: Swiss Re puts 2025 insured natural catastrophe losses at $107 billion and the trend level for 2026 at $148 billion, growing 5 to 7 percent a year.5

Exhibit 1

The Prudential Regulation Authority opened its 2026 priorities letter to insurers in January with "a continuing softening underwriting cycle in many lines of business" and warned that some firms are "making assumptions in their internal models about future underwriting performance that are overly optimistic."6 Our argument is that the binding constraint on AI in underwriting is not model capability or intake automation. It is that the appetite, meaning the definitions, thresholds, exclusions, referral triggers, precedents and authorities that make a submission right or wrong for a particular carrier, has never been made explicit, governed and machine-usable. In a hard market that gap is affordable. In 2026 it is the difference between selective growth and adverse selection, and regulators are now asking carriers to produce exactly the record it would create.

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About the authors

Jared D. Yerian

Jared D. Yerian, CFA, CIRA, CDBV, Senior Board Advisor, Penomic. Former Partner at McKinsey & Company, where he was one of five founders of the global Recovery & Transformation Services practice, and later Senior Partner and Co-Lead of Transformation at Oliver Wyman. He has served in CFO, CRO and board advisory roles on complex financial and operational transformations, restructurings and M&A. LinkedIn

Jennifer Kilian

Jennifer Kilian, Senior Board Advisor, Penomic. Former Partner at McKinsey & Company and Co-Founder and CEO of Cognition Capital. A transformation executive working where AI, digital product and experience-led growth meet, advising CXOs and boards. LinkedIn

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