Disclaimer: Insurance Rate Guard is not an insurance agency and does not provide professional financial advice. Our content is for educational purposes only. Please consult a professional advisor before making any financial decisions.
Not every car insurance rate filing is created equal. Some carriers file a rate change that barely moves the needle. Others file double-digit rate swings so large they would double or wipe out a driver’s premium overnight.
Our review of the SERFF filing corpus finds those two groups do not behave the same way at all. The biggest percentage swings, the double-digit rate swings that make for a scary headline, turn out to be rare. They also land almost entirely on small books of business, not the carriers with millions of policyholders on the books.
Most of the Market Sits in the Flat Zone
Line up every filing in the corpus by the size of its swing, not its direction, and a clear pattern shows up fast. Small moves dominate. Big moves are the exception, and they get smaller as a share of the market the more extreme they get.
We sorted 1,641 dated 2026 filings, covering just over 100.9 million policyholders, into five buckets based on the absolute size of the rate change.
| SIZE OF SWING | FILINGS | % OF FILINGS | POLICYHOLDERS | % OF POLICYHOLDERS |
|---|---|---|---|---|
| Flat (0-2pp) | 936 | 57.0% | 66,340,283 | 65.7% |
| Modest (2-5pp) | 323 | 19.7% | 20,759,977 | 20.6% |
| Moderate (5-10pp) | 266 | 16.2% | 13,124,536 | 13.0% |
| Large (10-20pp) | 91 | 5.5% | 647,415 | 0.6% |
| Extreme (20pp+) | 25 | 1.5% | 52,076 | 0.1% |
Source: InsuranceRateGuard.com analysis of the proprietary SERFF filing corpus, snapshot taken July 19, 2026 (tools/serff_study_7_analysis.py).
More than half of all filings, 57.0%, land within 2 percentage points of flat. Weighted by policyholders, that flat zone covers an even bigger share of the market, 65.7%. Combine the two “large” and “extreme” buckets and you get filings of 10 percentage points or more. Those make up just 7.1% of filings and cover only 0.7% of the policyholders in this corpus.
Double-Digit Rate Swings Hit the Smallest Books
The headline number in a rate story is usually the percentage. A 20% hike sounds much scarier than a 2% hike. But percentage size and audience size run in opposite directions in this data, and that gap is the real story behind double-digit rate swings.
The 116 filings of 10 percentage points or more carry a median of 1,941 policyholders each. The typical filing across the entire corpus carries a median of 4,730 policyholders, more than double that. Filings under 2 percentage points, the flat zone, run a median close to the corpus average and cover 65.7% of the market between them.
That gap is not a coincidence. A carrier correcting rates on a small, niche book of business, a new state entry, a specialty product, a book with thin claims history, often needs a bigger swing to hit the right price. A carrier with millions of policyholders in a state has enough claims data to fine-tune rates in smaller steps, and enough scale that a huge single-year jump would draw regulatory and customer attention it does not want.
Double-digit rate swings are not rare because insurers avoid big corrections. They are rare because big corrections mostly happen on books too small to move the market-wide numbers.
Direction splits close to even inside the double-digit bucket. Of the 116 large and extreme filings, 69 are hikes (59.5%) and 47 are cuts (40.5%). A double-digit rate swing leans toward a hike, but not by an overwhelming margin.
Methodology: How We Built This Study
This study pulls from SERFF-Data/national_queue.csv, the proprietary SERFF filing corpus Insurance Rate Guard maintains from public state insurance department filings. Each row is one state-carrier rate program with an extracted rate_change_pp (percentage point change) and a policyholder count taken from the filing itself. We used 1,641 filings with a valid rate_change_pp and effective date, covering 100,924,287 total policyholders.
We bucketed filings by the absolute value of rate_change_pp, so a 15% cut and a 15% hike land in the same “Large” bucket even though they move a driver’s premium in opposite directions. “Double-digit” in this study means 10 percentage points or more in either direction. We then compared filing count against policyholder-weighted totals in each bucket to see whether the size of a swing tracks with the size of the book it hits.
One limit worth naming. This corpus tracks filings that clear IRG’s materiality and coverage screens, not every rate filing submitted nationwide, so the shares here describe the tracked corpus, not the full universe of SERFF activity. The pattern is consistent enough, and the sample large enough, that we treat it as directional for the broader market.
Which Carriers Show up Most in the Double-Digit Bucket
Allstate Corp is the single most frequent name among double-digit rate swings, appearing 30 times, roughly a quarter of the whole bucket. But frequency is not the same as direction.
| CARRIER GROUP | DOUBLE-DIGIT FILINGS | HIKES | CUTS | AVG. SWING SIZE |
|---|---|---|---|---|
| Allstate Corp | 30 | 15 | 15 | 17.2pp |
| Farmers Insurance | 7 | 4 | 3 | 14.0pp |
| Branch Financial | 7 | 2 | 5 | 16.7pp |
| Brookfield Wealth Solutions | 5 | 5 | 0 | 16.0pp |
| AIG | 4 | 4 | 0 | 20.4pp |
Source: InsuranceRateGuard.com analysis of the proprietary SERFF filing corpus (tools/serff_study_7_analysis.py). Table limited to carrier groups with 3 or more double-digit filings.
Allstate splits its 30 double-digit filings exactly down the middle, 15 hikes and 15 cuts. That even split matters. Showing up often in the extreme bucket does not mean a carrier is hiking hard across the board. It means Allstate files a lot of state-by-state rate programs, some of which land in unusually thin, volatile corners of its book, in both directions.
Farmers leans more toward hikes in its double-digit filings, 4 against 3 cuts, but the sample is small enough that a single filing shifts the split. AIG and Brookfield Wealth Solutions show every one of their double-digit filings as a hike, though each carries fewer than 30,000 combined policyholders across all of them, a small footprint next to the corpus total.
Where Double-Digit Swings Concentrate by State
Double-digit filings are not spread evenly across the map. Ten states account for a disproportionate share of the large and extreme filings we tracked.
| STATE | DOUBLE-DIGIT FILINGS |
|---|---|
| Texas | 10 |
| Colorado | 7 |
| Maryland | 7 |
| New York | 6 |
| Arizona | 6 |
| Tennessee | 6 |
Source: InsuranceRateGuard.com analysis of the proprietary SERFF filing corpus (tools/serff_study_7_analysis.py).
Texas leads with 10 double-digit filings, more than any other state we tracked. Colorado and Maryland tie for second with 7 each. That does not mean every driver in these states is looking at a huge rate move. It means these states host a higher volume of the smaller, thinner-book filings that tend to produce large percentage swings in the first place, alongside their much bigger, steadier carrier books that mostly sit in the flat zone.
The Single Largest Swings We Tracked
A handful of individual double-digit rate swings show just how far a percentage swing can stretch on a small enough book. Allstate filed a 53.4% rate hike in Vermont, effective April 28, 2026, covering 1,532 policyholders. On the other end, Drivers Edge Insurance Company cut rates 24.4% in Colorado, effective May 15, 2026, covering just 99 policyholders.
Neither filing moved the needle for the corpus as a whole. Both would be a life-changing bill for the drivers on those specific policies. That is the tension at the center of this study: the filings most likely to make headlines are, almost by definition, the filings least likely to be the one that lands on your renewal notice.
For drivers who want to check what is actually landing on real bills right now, not just the extremes, our rate tracker follows this SERFF corpus in near real time as new filings clear state review.
The Double-Digit Filings That Reached the Most Drivers
Most double-digit filings hit small books, but a few reached far more people than the bucket’s typical 1,941-policyholder median. These are the double-digit rate swings most likely to show up as a real renewal bill rather than a rare edge case.
| CARRIER | STATE | SWING | POLICYHOLDERS |
|---|---|---|---|
| Farmers Insurance | Texas | -10.1% | 141,853 |
| Farmers Insurance | Arizona | +12.0% | 43,893 |
| Southern Farm Bureau Casualty | Louisiana | -10.6% | 39,332 |
| Nationwide | New York | +19.0% | 38,482 |
| Farmers Insurance | Illinois | +16.8% | 34,598 |
Source: InsuranceRateGuard.com analysis of the proprietary SERFF filing corpus, filings SFMA-134817393, BRWS-134921166, SFBC-134913662, NWPP-134405520, and BRWS-134970320 (tools/serff_study_7_analysis.py).
Farmers shows up three times in this table alone, once cutting rates 10.1% for 141,853 Texas policyholders and twice hiking rates in Arizona and Illinois. Nationwide filed a 19.0% New York hike covering 38,482 policyholders, one of the largest single hikes by both percentage and audience in the entire corpus. A driver on any of these five filings got a double-digit swing that was very much real, not a statistical footnote.
How to Save on Insurance
A double-digit rate swing makes for a striking headline, but it is not the number that predicts your renewal. Here are five moves that fit what this data actually shows.
- Do not assume a scary percentage in the news applies to your policy. Double-digit rate swings cover under 1% of the policyholders in this corpus, most tied to small or specialty books.
- Check your renewal date against a fresh quote 60 to 90 days out, regardless of whether you have seen a rate-change headline about your carrier.
- If your carrier shows up often in filings, ask your agent whether the change applies to your specific state, product, and rating tier before you assume the worst.
- Compare at least three carriers side by side using the same coverage limits, so you catch a real gap even when your own renewal only moved a modest amount.
- Raise your deductible or drop coverage you do not need on an older vehicle if a genuine increase lands and a full carrier switch is not practical right now.
The headline number is the outlier, not the average. Most of the market sees flat-to-modest movement every renewal cycle, and the double-digit rate swings that make news are concentrated in a sliver of small or specialty books. Watching your own renewal notice still beats reacting to a scary industry-wide statistic.
Sources Used
- InsuranceRateGuard.com proprietary SERFF filing corpus, snapshot July 19, 2026 (SERFF-Data/national_queue.csv; analysis script tools/serff_study_7_analysis.py)
- NAIC Auto Insurance Database Report
- Insurance Information Institute: Auto Insurance Facts and Statistics