The loss ratio is the percentage of earned premium an insurer pays out in claims — calculated as claims paid (incurred losses) divided by earned premium — and is the primary measure of underwriting profitability published in NAIC annual financial statements (https://content.naic.org/sites/default/files/inline-files/2023-Annual-Statutory-Basis-Financial-Statements-Instructions.pdf). A loss ratio above 100% means the insurer paid more in claims than it collected in premium; below 100% indicates underwriting profit before expenses (https://www.fdic.gov/regulations/applications/pdf/fdi_acs_a.pdf).
Loss ratio = incurred losses / earned premium × 100. Incurred losses include paid claims plus the change in loss reserves (claims reported but not yet paid, plus IBNR — incurred but not reported). Earned premium is the portion of written premium that applies to the elapsed policy period, not the full written amount. NAIC regulatory context: State insurance regulators and the NAIC use loss ratios as a key solvency and market conduct indicator. Insurers filing annual statements under NAIC's Statutory Accounting Principles (SAP) report loss ratios by line of business. A persistently high loss ratio — especially in commercial lines — can trigger regulatory review under an insurer's risk-based capital (RBC) framework (https://content.naic.org/cipr-topics/risk-based-capital). The NAIC's IRIS ratio system flags insurers whose loss ratios diverge materially from industry benchmarks. Small business lending intersection: Lenders and brokers evaluating commercial insurance for borrowers (as a loan covenant or SBA collateral requirement) should understand that a borrower's insurer's loss ratio affects policy availability and renewal pricing. An insurer with a deteriorating loss ratio in a borrower's industry may non-renew, leaving the borrower uninsured — a material risk for collateral-backed loans. SBA SOP 50 10 7.1 requires evidence of adequate insurance as a loan condition (https://www.sba.gov/document/sop-50-10-standard-operating-procedure). Pure loss ratio vs. ultimate loss ratio: The pure loss ratio uses only paid losses; the ultimate loss ratio includes case reserves and IBNR. Reinsurers and sophisticated buyers focus on ultimate loss ratios because they capture the full expected cost of claims from a policy period, including long-tail liabilities that settle years later.
A 'good' loss ratio depends on the line of business and expense structure. For commercial lines (BOP, workers' comp, commercial auto), loss ratios of 55–70% are generally sustainable — they leave room for expenses (typically 25–35%) and a profit margin. NAIC publishes industry benchmarks by line in its annual statistical reports (https://content.naic.org/industry-information/industry-data). A loss ratio consistently above 80–85% for a line signals pricing inadequacy or adverse selection and often leads to rate increases or coverage restrictions.
Your business's own claims experience (experience modification factor in workers' comp) directly affects your premium. But insurer-level loss ratios also matter: if the overall loss ratio for your industry or line deteriorates, insurers adjust pricing for all policyholders in that segment, even those with clean loss records. NAIC state regulators must approve rate changes based on actuarial justification tied to loss ratio trends (https://content.naic.org/cipr-topics/rate-regulation).
No. Loss ratio measures only the claims component. Combined ratio = loss ratio + expense ratio (underwriting expenses / earned premium). A combined ratio below 100% means the insurer is profitable on underwriting alone; above 100% means it relies on investment income to break even. See the Combined Ratio glossary entry for more detail.