The Three Types of Rate Regulation Systems

Not all states handle car insurance rate approvals the same way. There are three primary regulatory models used across the U.S., and which one your state uses has a direct impact on how quickly — and how dramatically — your rates can change.

Prior Approval States

In prior approval states, an insurance company must submit a rate filing and receive explicit approval from the state's Department of Insurance (DOI) before the new rates can take effect. Regulators review the actuarial data, loss ratios, and financial projections submitted by the insurer and can approve, modify, or deny the request outright.

This model offers the strongest consumer protections but also means that even justified rate adjustments can take months to process. States like California, New York, Massachusetts, and Michigan use prior approval systems. California is notably the most restrictive — rate filings there averaged 185 days to process in 2025 (with a 4-quarter rolling average of 234 days) under the framework established by Proposition 103.

File-and-Use States

In file-and-use states, insurers submit their proposed rate changes to the state regulator and can implement them immediately (or after a short waiting period), without waiting for explicit approval. The state reviews the filing after the fact and can order changes or rollbacks if rates are found to be excessive or discriminatory.

States like Florida, Arizona, Ohio, Vermont, and Idaho operate under file-and-use frameworks. While this model allows insurers to respond quickly to market conditions, it places the burden of catching unreasonable increases on the regulator after you've already been charged.

Use-and-File States

Use-and-file is the most permissive model. Insurers begin charging the new rates immediately and file documentation with the state afterward. If regulators later determine the rates were excessive or discriminatory, insurers may be required to issue refunds to policyholders.

Understanding which system your state uses is the first step in knowing your rights. Learn more about insurance regulation by state and how it directly shapes what you pay.

How the Rate Filing Process Actually Works

Whether a state requires prior approval or uses a file-and-use system, every insurance company must go through a formal rate filing process. Here's what that looks like from the inside.

What Insurers Must Submit

When an insurer wants to change its rates, it submits a filing to the state's Department of Insurance — most commonly through the SERFF (System for Electronic Rate and Form Filing) platform used by the National Association of Insurance Commissioners (NAIC). A complete filing typically includes:

• Actuarial justification: Loss ratios, projected claims costs, expense data, and profit margin assumptions
• Supporting data: Historical claims data, trend analysis, and catastrophe modeling (if applicable)
• Rate comparison: Proposed rates vs. current rates for all coverage types
• Certification: A licensed actuary must certify the filing meets state standards

By law, rates in every state must satisfy three core standards: they must be adequate (so insurers can pay claims), not excessive (not gouging consumers), and not unfairly discriminatory (based on actuarial risk, not personal characteristics unrelated to risk). Learn more about how car insurance premiums are calculated to see exactly which individual factors feed into that actuarial process.

The Role of the State Insurance Commissioner

The state insurance commissioner — a position that is either elected or appointed depending on the state — oversees the review of all rate filings. Their department's actuarial staff examines the insurer's data, flags inconsistencies, and may request supplemental information before a decision is made.

The commissioner's office acts as a consumer watchdog. Regulators in prior approval states have real leverage — they can reject filings that are deemed excessive or insufficiently justified, keeping real money in drivers' pockets.

Typical Approval Timelines

Approval timelines vary widely depending on the state's regulatory model and staffing. Based on Milliman Q2 2025 industry data:

The countrywide average for personal auto rate filings was approximately 59 days per single quarter and 67 days on a 4-quarter rolling basis as of mid-2025 — up from 49 days in 2019, reflecting increased regulatory scrutiny. These timelines explain the 6-to-12-month lag consumers often notice between when insurers experience higher costs and when those costs appear on their bills.

How Rate Increases Affect You in 2026

The regulatory environment directly shapes the car insurance market consumers experience. In 2026, several key dynamics are playing out that every driver should understand.

The National Pricing Landscape

After years of sharp increases, car insurance pricing has moderated. Following a roughly 6% national premium drop in 2025, average full-coverage premiums in 2026 are estimated at $2,524–$2,697 annually depending on the data source and methodology — with national projections pointing to only a modest increase of under 1% for the year. However, individual state experiences vary dramatically — some states saw drops of over 30% while others climbed significantly due to localized risk, litigation environments, and regulatory differences. If you're seeing unexpected changes at renewal, our guide to car insurance policy renewal explains your rights and options.

AI and the Future of Rate Filings

One emerging issue reshaping the approval landscape is the use of artificial intelligence and machine learning in insurance underwriting and pricing. Insurers like Root, GEICO, and American Family have already had AI-based rate models — including random forest algorithms and telematics-driven pricing — approved in various state filings. Regulators in states like Nevada and Montana have started requiring explainability documentation such as variable importance rankings and SHAP plots before approving AI-influenced filings. The NAIC continues to monitor AI/ML use across the industry, with consumer access to rating data and fairness of pricing remaining top concerns. You can also learn how your quote can change between estimate and final price as a result of these underwriting processes.

Why Some States Have Faster Rate Changes

The speed at which rates change in your state comes down to three factors:

1. Regulatory model (prior approval vs. file-and-use)
2. DOI staffing and resources — understaffed departments take longer to review filings
3. Legislative environment — states with active reform agendas tend to see faster rate corrections in both directions

Florida is a standout 2026 example: its top five auto insurers are projecting an average 8% rate drop, with some carriers cutting rates even further. State Farm has made three cuts since 2024 totaling over 20%, while AAA has made four cuts and Progressive is returning over $1 billion in refunds. These reductions are a direct result of tort reform measures that drove Florida's personal auto liability loss ratio to 52.5% in 2025 — the lowest in 15 years — and changes that moved through the regulatory process relatively quickly under Florida's framework.

For a deeper look at how your state stacks up, see our guide to car insurance rate regulation by state.

Frequently Asked Questions

Can I challenge a car insurance rate increase?

Yes. Start by reviewing your renewal notice carefully to verify the rate change was applied correctly to your policy. If you believe the increase is in error or unjustified, you can file a complaint with your state's Department of Insurance. In prior approval states, you can also access the public rate filing on your state's DOI portal or through the NAIC's SERFF Filing Access tool at serff.naic.org to see the justification submitted by the insurer. Some states have a Consumer Counsel office that will advocate on your behalf at no cost.

What is a rate filing and where can I find mine?

A rate filing is the formal document an insurance company submits to state regulators to justify a change in its premiums. It includes actuarial data, claims history, expense projections, and a licensed actuary's certification. Most rate filings are public records — you can search for them on your state's Department of Insurance website or through the NAIC SERFF Filing Access portal. Understanding what's in a filing can help you evaluate whether an increase was genuinely supported by data.

Why do car insurance rates differ so much from state to state?

State-by-state rate variation comes from a combination of factors: local claims costs, litigation environments, weather and catastrophe risk, minimum coverage requirements, and — critically — the state's regulatory model. A prior approval state like California may suppress rate increases in the short term, while a file-and-use state allows quicker market-responsive pricing. Understanding how car insurance premiums are calculated can help you see the full picture of what drives your specific premium.

How long does a state have to approve or deny a rate filing?

This depends entirely on the state. In prior approval states, regulators typically have a statutory review window — often 30 to 60 days — before a filing is approved, denied, or "deemed approved" by inaction. However, regulators can extend the review period by requesting additional information, which is why California's average stretches past 185 days. In file-and-use and use-and-file states, there is no pre-approval deadline since the insurer can implement rates immediately or shortly after filing.

Does regulation actually keep car insurance rates lower?

The evidence is mixed. Prior approval regulation does tend to slow the pace of rate increases, and active regulators can block significant unjustified premium hikes before they reach consumers. However, overly restrictive regulation can also reduce competition — if insurers can't price risk accurately, some may exit a market entirely, reducing consumer choice. California's market, for example, has seen major insurer pullbacks partly tied to the lengthy Proposition 103 approval process. The most consumer-friendly outcomes tend to come from states that balance robust regulatory oversight with a competitive insurance market.