An insurer cannot simply decide what to charge. Rates for most personal lines are filed with state regulators, supported by actuarial justification.
The standards a rate must meet
State rating laws generally require that rates be adequate, not excessive, and not unfairly discriminatory. Those three conditions frame every filing.
Adequacy protects solvency, since chronically underpriced coverage eventually threatens the insurer's ability to pay claims.
The prohibition on unfair discrimination does not bar distinguishing between risks. It bars distinctions that are not supported by expected differences in loss.
What is in a filing
A filing presents historical loss experience, adjustments for trends in claim frequency and severity, expense provisions and a provision for profit and contingencies.
Losses are developed to account for claims not yet fully settled, and trended forward to the period the rates will apply, since past experience is stale by the time it is used.
Rating plans specifying how characteristics affect the premium are filed alongside the overall rate level, and both are subject to review.
Prior approval and file and use
Some states require approval before rates may be used, while others allow rates to take effect on filing subject to later review and possible disapproval.
The difference substantially affects how quickly an insurer can respond to changing loss costs, and it is a persistent point of contention between industry and regulators.
A few lines and states operate with less rate oversight entirely, relying on competition to discipline pricing.
Why filings can stall
Regulators may question the trend assumptions, the expense provisions or the profit provision, and negotiation over those elements can extend review considerably.
Filings that would produce large increases attract more scrutiny, and political attention to affordability can slow the process independent of the actuarial support.
Where an insurer concludes it cannot obtain adequate rates, its response is usually to restrict new business in that state rather than to write at the approved level.
The role of advisory organizations
Advisory organizations collect loss data across insurers and publish prospective loss cost estimates that smaller insurers can adopt with their own expense adjustments.
This lets an insurer without credible data of its own file rates supported by industry-wide experience rather than a thin sample.
Each insurer still files its own multiplier and rating plan, so the shared data supports pricing without producing identical rates across the market.