How P&C Insurance Companies Make Money

Underwriting Profit and Investment Income

P&C insurers earn money from two primary sources: underwriting profit and investment income. Underwriting profit occurs when premiums collected exceed claims paid and operating expenses. The combined ratio (losses plus expenses divided by premiums) measures underwriting performance, with a ratio below 100% indicating underwriting profit. However, many P&C lines operate at a combined ratio near or above 100%, meaning the industry frequently breaks even or loses money on underwriting alone.

The Investment Float

Investment income is often the larger contributor to overall profitability. Insurers collect premiums upfront and pay claims later, sometimes years later for long-tail lines. This "float" is invested in bonds, stocks, and other assets, generating investment returns. Warren Buffett has famously described insurance float as a source of low-cost or even negative-cost capital. The combination of modest underwriting results and strong investment returns allows well-managed P&C companies to deliver consistent profits over time.