US P&C Insurance Industry Faces Growth Contraction in 2026 Despite Decade-Best Underwriting

The US property and casualty insurance industry faces a challenging growth environment in 2026 even as its underwriting performance reaches multi-year highs, according to the latest 'P&C Economics and Underwriting Projections: A Forward View' briefing from the Insurance Information Institute (Triple-I) and actuarial consulting firm Milliman.

The headline forecast is a notable contraction: underlying P&C industry growth is projected to fall to -3.7% in the first half of 2026, down sharply from 1.6% in 2025. Triple-I and Milliman expect recovery to begin in 2027 and 2028, though insurers are likely to remain under pressure from economic uncertainty and elevated loss trends in the intervening period. The organizations also forecast replacement cost growth of 2.1% during the first half of 2026, unchanged from 2025 levels — though they expect replacement-cost inflation to accelerate again through 2028 and eventually rise faster than overall US inflation.

Paradoxically, this weaker growth outlook follows a year of strong underwriting results. The sector's net combined ratio (NCR) — a key measure of underwriting profitability where below 100% indicates a profit — fell to its lowest level in more than a decade in 2025. This reflected improved conditions across several major lines after years of severe catastrophe losses, claims inflation, and post-pandemic market disruption.

Michel Léonard, Chief Economist and Data Scientist at Triple-I, emphasized that the 2025 results should be viewed in the context of the significant financial strain insurers have faced in recent years. While conditions have stabilized somewhat, he noted that insurers continue to operate in an environment marked by elevated catastrophe risk, inflationary pressures, and economic uncertainty. The 2026 growth contraction reflects a maturing rate cycle: after years of aggressive premium increases to restore profitability, insurers are now seeing slower premium growth as the market normalizes. For consumers, this could eventually translate into more stable pricing, though the persistence of catastrophe and inflation risks means the outlook remains uncertain.