The System Behind Every Rate Increase

Car insurance rates don't go up simply because an insurer decides to charge more. Every rate change — whether an increase or a decrease — must first pass through a formal regulatory review process administered by your state's Department of Insurance (DOI). This system is designed to ensure rates are not excessive, not inadequate, and not unfairly discriminatory.

Insurers submit what are known as rate filings — formal documents packed with actuarial data, loss projections, expense details, and underwriting profit margins — to state regulators for review. These filings are submitted electronically through systems like SERFF (System for Electronic Rate and Form Filing), a platform supported by the National Association of Insurance Commissioners (NAIC) that allows insurers to file with multiple states using a standardized format.

Once filed, regulators review whether the proposed rates are justified. The type of review — and how long it takes — depends heavily on which regulatory model your state uses. Understanding how state insurance regulation affects your car insurance rates is one of the most overlooked factors in what you actually pay.

What Insurers Must Include in a Rate Filing

For a filing to be accepted, insurers must provide substantial supporting documentation. Regulators in most states require the following:

Proposed rates must be "reasonable and justifiable" — they can't be excessive (overcharging), inadequate (dangerously low for solvency), or discriminatory. No uniform national definition of "excessive" exists, which is why regulators in different states may reach different conclusions on the same filing. To understand how these factors directly affect your bill, see our guide on how car insurance premiums are calculated.

Prior Approval vs. File-and-Use vs. Use-and-File States

The single biggest variable in how rate changes reach you is your state's regulatory model. There are three primary systems used across the U.S., each with a different balance between consumer protection and market flexibility.

Prior Approval States

In these states, an insurer must receive explicit approval from the state insurance commissioner before a new rate can take effect. Regulators review the full filing and may approve it, request modifications, or deny it outright. California, New York, Massachusetts, Maryland, Hawaii, and Michigan are prominent examples. This model provides the strongest consumer safeguards but often results in the longest approval timelines. Based on Milliman Q2 2025 data, California averaged approximately 185 days on a rolling four-quarter basis for private passenger auto rate filings — with a single-quarter countrywide average of 59 days and a 4-quarter rolling average of 67 days across all states.

File-and-Use States

Insurers file rates with the DOI and can begin using them immediately — or after a short statutory waiting period — while regulators review the filing. If a rate is later found to be excessive or unjustified, the insurer may be required to issue refunds. This model is faster for the market but offers less upfront protection. North Carolina, for example, averages around 17 days from filing to implementation under this framework.

Use-and-File States

The most permissive model. Insurers implement new rates first and file the supporting documentation with regulators afterward. Regulators retain the authority to object and require adjustments, but scrutiny is minimal at the point of implementation. States like Arizona use this approach with a 30-day post-implementation filing window.

The Role of the State Insurance Commissioner

The state insurance commissioner is the chief regulator overseeing the insurance market in each state. Their core responsibilities include protecting policyholders from excessive or discriminatory rates, ensuring insurers remain solvent enough to pay claims, and maintaining a competitive market.

When a rate filing comes in, the commissioner's Rate Regulation Division evaluates:

• Whether the actuarial assumptions are sound and well-supported
• Whether the loss trends reflect actual data rather than speculation
• Whether the proposed rating factors are risk-based and not discriminatory
• Whether the insurer's profit target is reasonable relative to their loss history

In prior approval states, the commissioner has direct authority to approve, modify, or deny rate requests. In states with a public intervenor system — most notably California — members of the public or advocacy groups can formally intervene in the review process and challenge a proposed increase before it takes effect. In California, for instance, consumer advocacy groups like Consumer Watchdog have reported saving consumers over $166 million through the intervenor process — including trimming individual insurer requests such as reducing a 22% proposed hike to 17%.

Pennsylvania's regulatory body also demonstrated active oversight in early 2025, denying over $210 million in rate requests filed by auto insurers — a clear example of how prior approval oversight can directly protect consumers.

How Long Does Approval Actually Take?

Approval timelines vary dramatically by state and have been trending longer as filing volumes increase. According to Milliman Q2 2025 data, the countrywide single-quarter average days to approval stands at approximately 59 days, with a 4-quarter rolling average of 67 days. Perr&Knight's Q3 2025 data puts the national median even higher at 71 days. Here's how some key states compare:

Slow approval timelines in prior approval states can create market friction. When insurers can't price for current risk levels quickly enough, some may reduce their footprint in that state or stop writing new policies altogether. This tension between consumer protection and market availability is central to ongoing insurance regulation debates in 2026. Understanding what factors affect your car insurance rates can help you anticipate when a rate filing is likely coming your way — and how large it might be.

Key 2025 State Law Changes That Affect Filings

Several states updated their minimum liability limits in 2025, which directly triggered new rate filings across the industry:

These legislative changes required insurers to file updated rates to reflect new coverage baselines — meaning even drivers who didn't change their policy may have seen premium adjustments tied directly to new state minimums.

How Consumers Can Challenge Rate Increases & What 2026 Looks Like

Challenging a Rate Increase

If you believe a rate increase was applied incorrectly, is unfairly discriminatory, or was never properly approved, you have formal avenues to push back:

1. Review your rate change notice — Insurers are required to notify you of premium changes, often 30 to 45 days in advance. Check whether the change aligns with a state-approved rate filing.
2. Access the public rate filing — Search your state DOI's website or the NAIC's SERFF Filing Access portal to verify the rate change is on file.
3. Contact your insurer first — Many state DOIs require you to attempt resolution directly with your insurer before escalating. Ask for a detailed breakdown of the increase and request applicable discounts.
4. File a complaint with your state DOI — Submit a formal complaint online, by phone, or by mail. Regulators will investigate whether the insurer applied approved rates correctly. This service is free to consumers.
5. Escalate to the NAIC — If your state DOI is unresponsive, the NAIC's Consumer Insurance Search tool can direct you to the appropriate authority.
6. Shop competing carriers — Even if the rate was approved and properly applied, you're never locked in. Comparing quotes at renewal can often save more than a formal challenge.

The Regulatory Landscape in 2026

After two years of sharp premium increases driven by inflation, supply chain disruptions, and rising claims costs, 2026 is shaping up to be a year of significant moderation for most drivers. According to ValuePenguin's State of Auto Insurance 2026 report, car insurance prices are projected to increase by approximately 0.67% on average nationally — the smallest year-over-year change in several years.

However, the story is highly uneven across states. Nineteen states are projected to see rate increases, while the majority are expected to see flat or declining rates. States with the steepest hikes in 2026 include:

California's situation is particularly instructive. Years of delayed rate approvals — driven by the state's rigid prior approval system and Proposition 103 — created a backlog of unfiled increases. Now, as the state allows more catch-up adjustments, drivers are seeing larger-than-average hikes despite living in one of the most regulated insurance markets in the country. There's also an active ballot initiative in California that cleared circulation in October 2025, which would eliminate the requirement for the commissioner to pre-approve rate changes — a development worth closely watching.

On the legislative front, tariff-driven auto parts costs are also exerting upward pressure on pending filings nationally, with import tariffs on auto parts potentially adding 7–19% to repair costs over time. Learn more about how 2026 car insurance rate increases are playing out across the country.

Frequently Asked Questions

Do all states require prior approval before car insurance rates go up?

No — only about 15 states use a true prior approval system where a rate cannot take effect until the insurance commissioner explicitly approves it. The remaining states use file-and-use or use-and-file models that allow rates to go into effect before or immediately upon filing. This means that in most states, a rate increase can reach your policy before a regulator has fully reviewed it for fairness.

How do I find out if a rate increase on my policy was actually approved by my state?

Rate filings are public records in most states. You can search your state Department of Insurance's website directly, or use the NAIC's SERFF Filing Access portal (filingaccess.serff.com) to look up approved filings by company, state, and line of business. Your rate change notice should reference the filing date and approval, which you can then cross-reference.

Can the state insurance commissioner reject a rate increase entirely?

Yes, in prior approval states the commissioner has full authority to deny a proposed rate increase if the actuarial justification is deemed insufficient, the rate is considered excessive, or the filing contains discriminatory pricing factors. Pennsylvania's regulator, for example, denied over $210 million in rate requests in early 2025. In file-and-use or use-and-file states, the commissioner can still order a rate rollback after the fact, but this is far less common in practice.

Why are car insurance rates changing more slowly in 2026 compared to recent years?

After significant premium increases in 2022–2024 driven by inflation, supply chain issues, and surging repair costs, most insurers have caught up to their target loss ratios. Regulators approved many of the large rate hike requests during 2023–2025, so the pipeline of pending increases has shrunk considerably. The national average increase for 2026 is projected at under 1%, though states like New Jersey and Nevada are still seeing meaningful hikes due to state-specific regulatory and cost factors.

What should I do if I think my car insurance rate increase was applied incorrectly?

Start by reviewing your renewal notice and comparing it against the approved rate filing on your state DOI's website. If the increase exceeds the approved percentage or was applied to the wrong coverage type, file a formal complaint with your state's insurance department — regulators investigate these at no cost to you and can require the insurer to issue a refund. In the meantime, comparing quotes from competing carriers is always advisable, as a rival insurer may offer the same coverage at a significantly lower price even if the increase was valid.