What Drives Car Insurance Cost: The Rating Factors, the Public Data, and How to Check Your Own Increase
Key takeaways
- Your premium is built from your record, mileage, location, age, car, credit where allowed, and the coverage you choose. Triple-I lists each one.
- The federal price index for motor vehicle insurance rose 19.1% and then 16.5% in the two years to August 2024, by our calculation from BLS data. In the year to August 2026 it fell 5.1%.
- Some factors you control (deductibles, coverage, the car you buy, shopping around). Others you do not (state costs, claim trends). Knowing which is which tells you where to push.
- Our benchmark checker compares your renewal with the federal index so you can tell a market move from a personal one.
This is the cost section of our car insurance guide. It explains what moves a premium, shows the public data on price trends, and links to the guides and tool that go deeper on each cost question.
What factors affect car insurance rates?
Triple-I's list of what commonly determines an auto premium is the clearest starting point. Not every insurer weighs these the same way, and some states restrict a few of them.
| Factor | What Triple-I says | Can you change it? |
|---|---|---|
| Driving record | Accidents or serious violations mean you will likely pay more; new drivers without a track record may too | Over time |
| How much you drive | More miles, more chance of accidents; "pleasure use" pays less | Sometimes |
| Where you live and park | Urban drivers pay more than small-town drivers; litigation, medical and repair costs vary by area | Rarely |
| Age | Insurers generally charge more if drivers under 25 use the car | No |
| Gender | Statistically, women have fewer and less serious accidents than men | No |
| The car | Its cost, theft likelihood, repair cost, engine size and safety record | At purchase |
| Credit-based insurance score | Used where state law allows | Over time |
| Coverage and deductibles | Limits, deductibles and optional coverages all affect price | Yes |
Triple-I also notes that it is illegal to use race or religion to set insurance rates.
How much have car insurance prices risen?
The Bureau of Labor Statistics publishes a monthly price index for motor vehicle insurance. BLS explains that it follows real policies but prices them with the drivers, vehicles and coverages held constant, so the index measures price change, not changes in what people buy. Comparing each August with the one before:
Over the full five years from August 2021 to August 2026, the index rose 49.8%, even after the latest decline. In its August 2026 release, BLS said the index "declined 0.8 percent in August after falling 0.3 percent in July."
The state regulators' own data points the same way for earlier years. The NAIC's 2023 Auto Insurance Database Average Premium Supplement, released July 8, 2025, reported that combined average premiums rose 14.41% in 2023 and that average expenditures reached $1,281.60, up 19.21% since 2019.
Part of the run-up was repair cost. Writing for IIHS-HLDI in August 2026, Matt Moore cited BLS data showing the average price of vehicle repairs has risen more than 40% since 2020, and pointed to bigger vehicles, fancier equipment and more complex powertrains as causes.
Check your own number against the index: Our car insurance increase benchmark checker takes your old and new premium and the renewal month, and shows how far your change sits above or below the federal index for the same period. A large gap points to something personal or local, which is the part you can shop or dispute.
Which cost guides answer your question?
"Why is my EV so expensive to insure?" Our guide to why EV insurance costs more uses Highway Loss Data Institute claim data to separate what is true about electric vehicles from what is true about expensive vehicles.
"Do I save by putting two cars on one policy?" How multi-car insurance discounts work explains who counts as your household, which vehicles qualify, and how the discount interacts with bundling.
"What will adding my teenager cost?" Adding a teen driver covers the cost and the choices that change it. The North Carolina Department of Insurance notes that a teen's rate should apply to the vehicle the teen principally operates, not automatically the most expensive car.
"Does my credit affect my rate?" In most states it can. The NAIC's 2019 brief says Hawaii, Massachusetts and California prohibited using credit history in underwriting or rating auto insurance, and that states typically do not allow a credit-based score to be the sole basis for a renewal increase or non-renewal. The NAIC keeps a state-by-state chart, updated March 19, 2026. Our car insurance credit score by state guide summarizes it.
What can you do about the cost?
Triple-I's list of ways to lower premiums includes three that move the number the most for most people:
- Raise your deductible if you have the cash to cover it. Triple-I says going from a $200 to a $500 deductible could reduce collision and comprehensive cost by 15 to 30 percent, and a $1,000 deductible can save 40 percent or more.
- Check insurance cost before you buy a car. Premiums are based partly on the car's price, repair cost, safety record and theft likelihood.
- Shop around. Triple-I says to get at least three quotes, and notes that "a company that offers few discounts may still have a lower overall price."
FinanceRazor may be paid when you request quotes through this link. This does not change what we report.
Frequently asked questions
Why is car insurance so expensive right now?
Prices climbed sharply in 2022 through 2024 as claim and repair costs rose. The BLS index is now falling, 5.1% below a year earlier as of August 2026 by our calculation, but premiums still sit far above 2021 levels.
Does the color of my car affect my rate?
No. Triple-I's auto insurance myths page says color does not factor into the price. Make, model, body type, engine size, age, price, repair cost, safety record and theft likelihood do.
Do all insurers use the same rating factors?
No. Triple-I says not all companies use the same parameters, and state law limits some factors, such as credit in Hawaii, Massachusetts and California according to the NAIC.
Is my increase normal if the national index went down?
Possibly not. A national decline does not stop an individual increase, because your state, insurer and household all move separately. The benchmark checker measures the gap.
What is the cheapest way to cut my premium without dropping coverage?
Ask for every discount you qualify for, consider a higher deductible you can afford, and compare at least three quotes for identical coverage.
Sources
- U.S. Bureau of Labor Statistics, CPI-U series CUUR0000SETE, Motor vehicle insurance, U.S. city average, not seasonally adjusted, https://data.bls.gov/timeseries/CUUR0000SETE, data extracted October 1, 2026.
- U.S. Bureau of Labor Statistics, "Consumer Price Index Summary," August 2026, released September 11, 2026, https://www.bls.gov/news.release/cpi.nr0.htm, accessed October 1, 2026.
- Insurance Information Institute, "What determines the price of an auto insurance policy?," https://www.iii.org/article/what-determines-the-price-of-an-auto-insurance-policy, accessed October 1, 2026.
- U.S. Bureau of Labor Statistics, "Measuring Price Change in the CPI: Motor vehicle insurance," last modified May 20, 2026, https://www.bls.gov/cpi/factsheets/motor-vehicle-insurance.htm, accessed October 1, 2026.
- Insurance Information Institute, "8 auto insurance myths," https://www.iii.org/article/8-auto-insurance-myths, accessed October 1, 2026.
- Insurance Information Institute, "Nine ways to lower your auto insurance costs," https://www.iii.org/article/nine-ways-to-lower-your-auto-insurance-costs, accessed October 1, 2026.
- National Association of Insurance Commissioners, "NAIC Releases '2023 Auto Insurance Database Average Premium Supplement'," July 8, 2025, https://content.naic.org/article/naic-releases-2023-auto-insurance-database-average-premium-supplement, accessed October 1, 2026.
- National Association of Insurance Commissioners, "Credit-Based Insurance Scores," last updated March 19, 2026, https://content.naic.org/insurance-topics/credit-based-insurance-scores, accessed October 1, 2026.
- National Association of Insurance Commissioners, "Use of Insurance Credit Scores in Underwriting," July 2019, https://content.naic.org/sites/default/files/government-affairs-brief-credit-insurance-scores.pdf, accessed October 1, 2026.
- North Carolina Department of Insurance, "FAQs About Auto Insurance," https://www.ncdoi.gov/consumers/auto-and-vehicle-insurance/faqs-about-auto-insurance, accessed October 1, 2026.
- Matt Moore, IIHS-HLDI, "How crash avoidance tech simultaneously raises and slashes repair costs," August 11, 2026, https://www.iihs.org/news/detail/how-crash-avoidance-tech-simultaneously-raises-and-slashes-repair-costs, accessed October 1, 2026.
This page is general information, not insurance advice. Rating rules vary by state and by insurer.