Insurance Research Council studies on uninsured drivers and claims

The Insurance Research Council (IRC) is the source behind most of the uninsured-driver percentages and injury-claim trends you see quoted in news stories about car insurance. Its best-known finding is that 15.4% of U.S. drivers were uninsured in 2023, and one in three was either uninsured or underinsured. Its other studies track why injury claims cost more each year and how litigation affects premiums.

Who the Insurance Research Council is

According to the Insurance Research Council, it is an independent, nonprofit research organization founded in 1977 and supported by property and casualty insurers and industry associations. It is affiliated with The Institutes, does not lobby, and says it does not advocate policy positions.

That funding model matters when you read its work. The data is generally sound and widely used by regulators and journalists, but the questions the IRC chooses to study (claim costs, attorney involvement, fraud, litigation) are the ones insurers care about. Read the findings as measurements, and read the framing with that context in mind. Our guide on how to read car insurance rate studies and average-cost claims covers the same habit for other publishers.

The uninsured motorist study

The IRC's uninsured motorist estimates are the standard national figures. Its study published in February 2025 covers 2017 through 2023.

What it found

Source: Insurance Research Council 2025 study, via the Insurance Information Institute.

Other findings from the IRC's February 2025 release:

• One in three drivers (33.4%) was uninsured or underinsured in 2023, up about 10 percentage points since 2017.
• Highest uninsured rates (2023): Mississippi 28.2%, New Mexico 24.1%, District of Columbia 23.1%. The III's table adds Michigan (22.3%) and Tennessee (21.3%) to the top five.
• Lowest uninsured rates (2023): Maine 5.7%, Utah 6.2%, Idaho 6.4%, followed by Wyoming (6.7%) and Montana (7.2%).
• Nearly every state's uninsured rate rose in 2020 during the pandemic. From 2020 to 2023 results were mixed: Michigan had the largest decline and Washington the largest increase.
• Underinsured rates rose almost everywhere from 2017 to 2023, except in New York and the District of Columbia.

For every state's figure, see uninsured drivers by state or the state guides, such as Mississippi and Maine.

How the IRC measures it

Nobody can count uninsured cars directly, so the IRC uses claims. Its estimate is the ratio of uninsured motorist coverage claims (people hurt by an uninsured driver) to bodily injury liability claims (people hurt by an insured driver). If uninsured-motorist claims are high relative to liability claims in a state, more of the at-fault drivers there must be uninsured.

Two consequences follow:

1. The figure measures uninsured drivers involved in injury crashes, not uninsured registered vehicles. It can differ from DMV or state database counts.
2. "Underinsured" is measured the same way, using underinsured motorist coverage claims. It means the at-fault driver had some coverage but not enough to pay the injured person's damages.

Injury claim and litigation studies

Uninsured drivers are only one part of the IRC's work. Most of its recent studies examine why bodily injury claims keep getting more expensive.

• Auto Injury Insurance Claims: A Study of Increasing Claim Severity (published July 30, 2026). It introduces the IRC's Auto Injury Claims Analytics Database, built from more than 7.4 million paid injury claims at nine insurers that together write about 43% of the U.S. private passenger market, covering mid-2017 to mid-2022. Earlier IRC research found the average injury claim payment rose from about $14,000 in 2017 to more than $20,000 in 2022, and the share of claimants represented by an attorney rose from about 40% to nearly 50%.
• Estimating the Value of Increased Litigation: A Review of Motor Vehicle Tort Cases (September 15, 2025). Looking at 2014 to 2023 court data, it estimated $42.8 billion of "excess" value in motor vehicle tort filings, meaning litigation growth beyond what accident trends would predict. Federal motor vehicle tort filings rose 4.9% a year while accident frequency fell.
• Personal Auto Insurance: Variations in Affordability (November 25, 2025). It ranks states by an affordability index, the ratio of average auto insurance expenditure (from NAIC data for 2023) to median household income, and breaks the differences into eight cost drivers: accident frequency, repair costs, the tendency to file injury claims, injury claim severity, claim expenses, uninsured and underinsured rates, and litigation.
• Public Opinions on Attorney Involvement in Auto Insurance Claims (October 1, 2026), a survey of more than 2,000 people about attorney advertising, litigation funding and claim experiences.

These studies feed the industry's argument about social inflation, the idea that rising lawsuits, larger settlements and the occasional nuclear verdict push liability premiums up faster than crash trends alone. Our guide on social inflation and nuclear verdicts: how lawsuits raise premiums explains that debate, including the counterarguments from consumer and trial-lawyer groups.

What the findings mean for your policy

The research is mostly useful for one decision: how much protection to buy against other drivers.

1. Price uninsured and underinsured motorist coverage first. If roughly one in three drivers in a crash has no insurance or not enough, your own UM/UIM coverage is what pays your medical bills and lost wages. See uninsured and underinsured motorist coverage explained.
2. Match UM/UIM to your liability limits. Many states let you buy UM/UIM up to your own liability limits. It is usually cheaper than people expect compared with the gap it closes.
3. Check your state's rate. In a state like Mississippi, where the IRC estimated more than one driver in four was uninsured in 2023, uninsured motorist coverage matters even more. Whether UM is required or optional varies by state; check state car insurance requirements lookup.
4. Do not count on suing. Underinsured and uninsured drivers rarely have assets to collect from. The IRC's numbers are a reminder that the at-fault driver's policy limit is often the ceiling on what you recover from them.
5. Use the How much car insurance do I need? to size liability and UM limits against what you own.

A worked example

Say you are hit by a driver carrying a 25/50/25 policy and your injuries come to $70,000 (a hypothetical figure). The other driver's insurer pays its $25,000 per-person limit. Without underinsured motorist coverage, the other $45,000 is yours to recover from a driver who probably cannot pay. With $100,000 of UIM coverage, your insurer pays the rest, subject to your state's rules on how UIM is calculated.

Limits of the data

• It lags. The newest uninsured estimates describe 2023. Rates may have changed since.
• It is an estimate. The claims-ratio method is consistent over time, which is why it is useful for trends, but a single state's figure can move because of claim patterns rather than changes in how many people buy insurance.
• Full reports are paid. The IRC publishes free summaries; full reports are free for members and sold to others. News coverage often repeats a single headline figure without the context.

Key takeaways

• The Insurance Research Council is an insurer-supported nonprofit research group; its numbers are widely used, but read its framing with that in mind.
• It estimated 15.4% of drivers were uninsured in 2023, and 33.4% were uninsured or underinsured.
• Mississippi had the highest uninsured rate (28.2%) and Maine the lowest (5.7%) in 2023.
• Its injury-claim and litigation studies underpin the "social inflation" explanation for rising liability premiums.
• The practical lesson for drivers: buy uninsured and underinsured motorist coverage at limits that match your own liability coverage.