In mid-2024, a single regulatory filing quietly rewrote the mathematics behind auto liability insurance for roughly 40% of insured vehicles in California. The filing, submitted by Verisk Analytics and approved by the state's insurance commissioner, updated the loss-cost multipliers that underpin personal auto liability coverage. It was the first major revision to base rates since 2018, and its effects rippled through the market within months. Insurers repriced books, consumer advocates raised alarms, and the state's insurance department published a 47-page decision explaining its reasoning.

A Single Filing Altered Rate Adequacy for Millions of Drivers

Verisk's 2024 private-passenger auto rate filing, approved by the California regulator in mid-2024, targeted the loss-cost multipliers that insurers use to calculate base premiums for liability coverage. These multipliers, derived from historical claim data, adjust for inflation, driving patterns, and regional risk. The filing shifted the multipliers upward in urban zip codes and downward for low-mileage drivers, reflecting updated claim-frequency assumptions by county. According to the state's insurance department, the changes affected roughly 40% of insured vehicles in California, or several million drivers.

The filing also reallocated weight between bodily injury (BI) and property damage (PD) coverages. BI loss costs increased due to rising medical expenses and claim severity, while PD loss costs moderated slightly as repair costs stabilized. The net effect was a modest increase in the average liability premium, but the distribution varied widely by driver profile. Urban drivers with long commutes faced higher increases; rural low-mileage drivers saw smaller changes or even decreases.

Verisk's role as a rating advisory organization means its filings serve as benchmarks for insurers that lack their own actuarial data. The company's rate recommendations are not binding, but they carry significant weight in a market where many small to mid-size carriers rely on advisory rates. The 2024 filing represented Verisk's updated view of loss trends, incorporating data through the end of 2023. It also reflected changes in driving behavior post-pandemic, with more people working from home and fewer miles driven overall.

The state's approval came after a public hearing and a 12-month monitoring order, which required Verisk to report actual loss experience against projections. Consumer advocates argued that the average increase of around 12% was too steep, while the Insurance Information Institute defended the filing as actuarially necessary. The commissioner noted in the decision that while the increase was significant, the alternative—inadequate rates leading to insurer insolvencies—posed a greater risk to consumers.

How the Filing Rewrote the Liability-Pool Math

At the core of the filing was a new categorization of driver risk tiers. Verisk introduced a refined classification that separated urban and suburban drivers more granularly, using zip-code-level data for claim frequency and severity. Previously, risk tiers were broader, grouping multiple zip codes with similar but not identical risk profiles. The new tiers narrowed the bands, increasing base premium for urban zip codes by as much as 15% for some, while reducing surcharges for low-mileage drivers who logged under 7,500 miles annually. Updated claim-frequency assumptions by county drove much of the change. Verisk's actuaries analyzed three years of loss data, adjusting for underreporting during the pandemic. They found that claim frequency in densely populated counties had returned to pre-pandemic levels, while frequency in rural counties remained lower. The filing also incorporated a trend factor for BI severity, which had been rising at roughly 5% per year due to medical inflation and higher settlement amounts.

The reallocation of weight between BI and PD coverages shifted the premium distribution. Historically, BI accounted for about 60% of the liability premium and PD for 40%. The filing moved the split closer to 65-35, reflecting faster growth in BI costs. For a typical policy, this meant the BI portion increased more than the PD portion decreased, resulting in a net increase. However, for drivers in low-claim areas, the PD reduction partially offset the BI increase. Verisk also revised its territory definitions, using updated census data to reflect population shifts. Some areas that had been classified as rural were reclassified as suburban, pushing them into higher-rate tiers. The changes were applied uniformly across all insurers using Verisk's advisory rates, creating a level playing field for carriers that lacked proprietary models. Insurers with their own actuarial teams could deviate, but many chose to adopt the new multipliers to align with market expectations.

Insurers Reacted by Repricing Their Books Within Months

Three top-10 carriers in California—State Farm, Allstate, and Progressive—filed new rates with the department within six months of the Verisk approval. State Farm adopted the new multipliers almost entirely, adjusting its liability rates upward by an average of 8% for existing policyholders. Allstate took a more selective approach, raising rates in urban areas by 12% but holding steady in rural regions. Progressive, which relies heavily on telematics data, used the filing to promote its usage-based program, offering discounts of up to 15% for low-mileage drivers.

Smaller mutuals and regional carriers waited for second-quarter data before filing. Many of these companies lacked the actuarial resources to develop independent rates and depended on Verisk's advisory rates as a safe harbor. By late 2024, roughly two-thirds of the state's personal auto insurers had filed rate changes, with adjustments ranging from -5% to +22% depending on the carrier and the driver profile. Some non-admitted carriers exited the state entirely, citing the increased regulatory scrutiny and the difficulty of competing with admitted carriers.

The rate changes triggered a wave of policyholder shopping. The state's insurance department reported that usage of its online rate-comparison tool spiked 300% in the months following the approval. Agents reported that clients who had been with the same insurer for years were suddenly shopping around, often finding lower rates with carriers that had been slower to adjust. The market became more fluid, with direct writers gaining share from independent agency carriers.

Reinsurers also took notice. Treaty terms for personal auto reinsurance were renegotiated in early 2025, with some reinsurers increasing attachment points for liability losses. The increased cost of reinsurance put additional pressure on primary carriers, particularly those writing in urban areas where the new loss-cost multipliers had already raised premiums. The interplay between the Verisk filing and reinsurance pricing created a feedback loop that further tightened underwriting standards.

Regulatory Approval Process Revealed Competing Interests

The public hearing on the Verisk filing drew testimony from consumer advocates, industry actuaries, and representatives of the state's insurance department. The Consumer Federation of America flagged the 12% average increase as excessive, arguing that it would disproportionately affect low-income drivers in urban areas. They submitted an analysis showing that the increase would add roughly $150 per year to the average policy, and urged the commissioner to reject the filing or order a phased implementation.

Industry actuaries, including those from Verisk and the Insurance Information Institute, defended the filing as actuarially necessary. They presented evidence that claim costs had risen faster than premiums since 2018, and that the filing would restore rate adequacy. They also noted that the filing included a 12-month monitoring order, which would allow adjustments if actual experience diverged from projections. The commissioner, in the 47-page decision, acknowledged both sides, stating that the filing struck "a balance between affordability and solvency."

The NAIC model law guided the review timeline, which required a decision within 90 days of the public hearing. The commissioner's staff conducted an independent actuarial review, which largely confirmed Verisk's loss-cost projections but noted that the trend selection for BI severity was at the high end of plausible ranges. The staff recommended a conditional approval with a monitoring order, which the commissioner adopted. The order required Verisk to submit quarterly reports on actual loss experience and allowed the department to order a mid-year adjustment if losses deviated by more than 5% from projections.

Consumer advocates criticized the approval as too lenient, while insurers praised it for providing certainty. The commissioner noted in the decision that "no alternative but to approve" was the conclusion after weighing the evidence. The monitoring order was a compromise that allowed the filing to take effect while keeping a regulatory check on its impact. As of mid-2025, the quarterly reports showed that loss experience was tracking close to projections, with no mid-year adjustment needed.

The Filing's Legacy: Tightened Underwriting and Shifting Market Share

One year after the filing, California's auto insurance market had undergone a notable shift. Direct writers—insurers that sell policies directly to consumers without agents—gained roughly 3 percentage points of market share, driven by their ability to quickly adjust rates and offer telematics discounts. Independent agency carriers, which had relied on Verisk's advisory rates, struggled to compete and saw their share decline. The shift accelerated a trend that had been underway for years, but the Verisk filing gave it new momentum.

Usage-based insurance programs saw a significant enrollment jump. Progressive's Snapshot and Allstate's Drivewise both reported increases of 20-30% in new enrollments in the state, as drivers sought discounts to offset the liability premium increases. Low-mileage drivers, in particular, found that telematics discounts could reduce their total premium by 10-15%, making usage-based policies more attractive than traditional ones. The trend encouraged other carriers to launch or expand their telematics programs.

The high-risk assigned-risk pool grew by 8% in 2025, as some drivers found themselves priced out of the standard market. The pool, which provides coverage to drivers who cannot obtain insurance in the voluntary market, saw increased demand from urban drivers with poor credit scores or prior claims. The growth in the pool put pressure on the state's guaranty fund, which covers losses from insolvent insurers, though no major insolvencies occurred. Reinsurers adjusted treaty terms for personal auto, increasing premiums for excess-of-loss coverage and tightening underwriting guidelines.

Verisk's competitive advantage was reinforced by the filing. The company's advisory rates became the de facto standard in the state, and other rating organizations faced pressure to update their own filings to remain relevant. The state's insurance department received inquiries from other states about the filing, and several expressed interest in adopting similar approaches. The filing's legacy extended beyond California, influencing rate regulation practices nationwide.

Trade-Offs and Unintended Consequences: A Closer Look

While the Verisk filing aimed to restore actuarial balance, it also introduced trade-offs that merit examination. One notable consequence was the widening gap between standard-market and non-standard insurers. Non-standard carriers, which specialize in high-risk drivers, saw a surge in demand as some standard carriers tightened eligibility requirements. For example, a driver with a single at-fault accident who previously qualified for a standard policy might now be relegated to the non-standard market, where premiums can be 30-50% higher. This shift raised concerns about affordability for drivers with imperfect records, even as it improved rate adequacy for standard carriers.

Another trade-off involved the impact on low-income urban drivers. Consumer advocates argued that the 12% average increase, while modest for some, could be crippling for households already struggling with rising living costs. They pointed to data showing that urban zip codes with median incomes below $50,000 experienced average premium increases of around 15-18%, compared to 5-8% in higher-income areas. The commissioner's decision acknowledged this disparity but noted that the alternative—inadequate rates—could lead to insurer insolvencies that would harm all policyholders. Critics countered that the filing could have included a phase-in period to soften the blow, but the commissioner opted for immediate implementation with a monitoring order.

Counter-arguments from the industry emphasized that the filing's granular risk tiers actually improved fairness for low-mileage drivers. For instance, a suburban driver who logs 6,000 miles a year saw a premium reduction of roughly 3-5%, while a similar driver under the old broad tiers would have paid the same rate as a high-mileage commuter. Telematics programs further enhanced this fairness, allowing safe drivers to earn discounts regardless of location. However, privacy advocates raised concerns about the data collection inherent in telematics, arguing that insurers could use the data to raise rates for drivers who deviate from average behavior, even if they are safe.

Reinsurance costs also introduced a feedback loop. As primary carriers raised rates in response to the filing, some reinsurers increased their attachment points for liability coverage, effectively reducing the amount of risk they would assume. This forced primary carriers to retain more risk, which in turn led to stricter underwriting and higher rates for certain driver segments. The net effect was a market that became more segmented, with clear winners (low-mileage, safe drivers) and losers (urban, high-mileage drivers with prior claims).

Practical Takeaways for Policyholders and Agents

For policyholders, the key takeaway is that loyalty no longer pays. The Verisk filing created wide rate disparities among insurers, and drivers who do not shop around at renewal may pay hundreds of dollars more than necessary. The state's insurance department offers a free rate-comparison tool that allows consumers to compare quotes from multiple carriers. Policyholders should use it annually, especially after a rate filing like this one.

Telematics discounts now offer a meaningful way to offset liability increases. Drivers who log fewer than 10,000 miles per year, or who drive safely, can save 10-15% by enrolling in a usage-based program. Agents should discuss these options with clients, particularly those in urban areas where standard rates have risen the most. However, telematics programs are not for everyone; drivers with long commutes or aggressive driving habits may see their premiums increase.

Agents must re-quote their entire book annually to ensure clients are not overpaying. The rate changes triggered by the Verisk filing are not uniform across carriers, and a client who was well-priced last year may now be overpaying by 10% or more. Agents should also monitor the state's rate-comparison tool and be prepared to switch carriers when it benefits the client. The market is more fluid than it has been in years, and agents who adapt will retain clients.

Expect more rate filings from other states that copy the Verisk model. The success of this filing—from both a regulatory and actuarial perspective—has encouraged other rating organizations to propose similar updates. The NAIC is also considering model legislation that would standardize loss-cost multiplier reviews every three years. Policyholders and agents should stay informed about regulatory developments in their states, as similar changes may be coming soon.

Policyholders should consult a licensed insurance agent or broker for advice tailored to their specific situation.