Methodology: how the ClearCarRates index is built

Primary source

The launch index uses the NAIC 2023 Auto Insurance Database Average Premium Supplement, released June 2025, covering written premium and exposure data for calendar years 2019 to 2023. We use three published measures.

• Combined average premium (Table 5): liability plus collision plus comprehensive average premiums for one insured vehicle.
• Average expenditure (Table 4): total written premium for liability, collision and comprehensive divided by liability written car years. This reflects the coverage mix people actually bought.
• Liability average premium (Table 1C): liability written premium divided by liability written exposures.

Countrywide 2023 figures in that supplement: combined average premium $1,438.46, average expenditure $1,281.60, liability average premium $737. NAIC reported combined average premiums increased 14.41% in 2023.

States included and excluded

The launch index covers 12 high population states where we verified the NAIC figures directly from the supplement PDF: California, Texas, Florida, New York, Pennsylvania, Illinois, Ohio, Georgia, North Carolina, Michigan, New Jersey and Virginia.

All other states are excluded from the launch index. That is a gap, not a judgment about those states. We would rather publish 12 verified state pages than 50 filled with numbers we did not check. States will be added only when the same tables can be verified for them.

Age bands

The NAIC supplement used here does not publish an age split. Our age pages therefore show no age specific dollar figure. They state the usual direction relative to the state benchmark and explain the factors behind it. Any site that gives you a precise national teen premium without a traceable source should be read with caution.

Trend context

For direction after 2023 we cite the Bureau of Labor Statistics Consumer Price Index for motor vehicle insurance. BLS reported that index was up 0.2% over the 12 months ended February 2026, in The Economics Daily dated March 19, 2026. A CPI index measures price change. It is not a state premium average and we never mix the two.

State minimum limits

Minimum limit notes on state pages are starting points compiled for orientation. Insurance law changes, and some states have policy form choices that change the picture. Confirm current requirements with your state insurance regulator before you rely on a minimum figure.

Verification record

Every figure in our checked in data file at src/data/rates.json carries sourceName, sourceYear and verifiedDate. Launch verification date: 2026-10-04. If a source is revised, we will update the figure, the year and the verified date together.

Known limitations

• 2023 is the most recent NAIC supplement year we could verify at launch. Premiums have moved since then.
• Averages hide wide variation by city, vehicle, record and insurer.
• Age, DUI, SR-22 and discount effects are insurer specific. We explain them qualitatively and do not invent national surcharges.