How much one at-fault accident raises your rate in different states

No, the "about 40 percent" figure is not true everywhere. A February 2026 quote study put the national average increase after one at-fault accident at 45.0%, but its state results ran from 16.5% in Pennsylvania to 70.7% in California, and a second study with a different sample driver reported roughly 60% nationally. The gap comes from three things: who the sample driver is, what the state lets an insurer charge, and what the insurer's own rating plan does with a claim.

The rest of this article takes those apart so you can read any accident-surcharge number, including the one on your own renewal notice, without being misled by it. The mechanics of how states build their point systems are covered in other articles; this one is about size, spread and why the headline averages disagree.

Where the "accident adds about 40 percent" claim comes from

Almost every state-by-state accident figure is a quote study, not a count of what drivers actually paid. A research team picks one hypothetical driver, collects insurer rates for that driver in each state with a clean record, collects them again with one at-fault accident added, and compares the two. The result is only as general as the driver they chose.

Two recent examples show how much the choice matters.

Sources: LendingTree's at-fault accident study, which uses Quadrant Information Services rate data pulled in January 2026, and Insurance.com's state-by-state accident analysis. Both are quote panels. Neither is an official statistic, and neither tells you what any single insurer will charge you.

Notice what the two share and what they do not. Both use a mid-aged driver with good credit and a clean record. Neither tells you the exact claim size beyond a floor, which insurers supply the quotes, or how many quotes sit behind each state's figure. A 45% average and a 60% average can both be honestly computed and still differ by fifteen points, simply because the samples differ.

Quote-study averages also move as insurers change their surcharge rules and base rates, so treat any figure you read, including these, as a snapshot with a date.

How wide the spread is between states

The LendingTree results are useful because they publish all 51 jurisdictions, in both percent and dollars. A selection:

Two readings matter here.

Percent and dollars rank states differently. New Hampshire is third in percent but its dollar increase ($926) is below the national average, because its starting premium is low. Arizona is eighth in percent yet first in dollars, at $2,091.75 a year. If you are budgeting, the dollar figure is the one that hits your account. If you are comparing how harshly a state's rating system treats an accident, the percent is closer, though still imperfect.

A percent depends on the base. A 50% increase on a $900 policy is $450. A 50% increase on a $3,000 policy is $1,500. States with expensive base rates can post a modest percentage and a heavy dollar hit. Louisiana's 46.8% sits just above the national average in percent but lands third in dollars.

The Insurance.com analysis tells the same story in a different form. It ranks states by the average annual rate after an accident rather than by the increase. As of its September 2026 update, it lists Louisiana, California, Florida, Michigan and Kentucky as the most expensive after an accident, and Maine, Vermont and New Hampshire as the least expensive. Michigan shows how the two lenses differ: fourth-highest in absolute post-accident cost in that analysis, yet 48th of 51 in LendingTree's percent ranking. Michigan's starting premium is high, so the accident adds a smaller slice of it. (The Insurance.com page is internally inconsistent on Louisiana's figure, giving different numbers in its introduction and its table, which is a small reminder to verify any single figure before quoting it.)

None of this means you can find your own surcharge in a table. It means the same event costs a clean-record driver anywhere from a few hundred to a couple of thousand dollars a year depending on the state, the insurer and the starting price.

Why the same driver gets a different percentage

Four forces produce the spread.

The rating plan converts an accident into a number

Most insurers file a surcharge or tier rule with the state, and the rule says what an at-fault accident does to the premium. Some use a flat percentage. Some move the driver to a higher-priced tier or take away a "claim-free" or "good driver" discount. Some use points. Two insurers in the same state can file very different rules, which is one reason the quotes for one driver vary so much from company to company. (See why two insurers quote the same driver very different prices.)

The state decides what counts as an at-fault accident

States disagree on how much fault is needed before a surcharge applies and on how small a claim can be before it is ignored. California's regulation, for example, treats a driver as principally at fault only when the driver's actions were at least 51 percent of the legal cause, and for an accident without injury requires that the total loss exceed $1,000, according to 10 CCR 2632.13 as published by Cornell's Legal Information Institute. That is a legal definition that governs how California insurers classify the accident, and it differs from the plain-language idea that "the other driver was mostly at fault, so I'm fine." See how fault is determined in a car accident for how the fault call itself is made.

The state caps or bars some surcharges

This is the section below on rules. In short: some states forbid surcharging for not-at-fault accidents, some set a dollar floor under which a small claim cannot be used against you, and some cap the size of the first surcharge.

The base rate and the discounts already in it

A driver who held a large discount, such as a good-driver or multi-policy credit, can lose the discount along with taking a surcharge. A driver with no such discounts has less to lose. The sample driver in a study usually carries the standard package, so the study reflects losing it.

States that limit surcharges: what the rules actually say

State rules on surcharges are not uniform and often have exceptions, so a general statement ("accident surcharges are legal in all states") is unreliable in both directions. These examples come from statutes, regulations and regulator guidance that I opened; none of them is a complete list of states with limits.

Three observations. First, the rules differ in kind: New York and Pennsylvania use dollar thresholds, Delaware regulates the surcharge's size and duration, Georgia and Florida focus on fault. Second, the two lowest percentages in the LendingTree list, Pennsylvania at 16.5% and New York at 22.4%, both belong to states with a claim-size threshold on the books. That fits a plausible explanation, but a quote study cannot prove that the threshold caused the low figure, because it does not state the exact claim amount it used. Third, none of these protections cover your own mistakes: a clearly at-fault accident above the threshold is surchargeable almost everywhere.

To see what applies in your state, start with the state car insurance requirements lookup and then read the state insurance department's consumer page or ask the department's help line. Rules change, and I could not confirm every state's current text, so check yours.

Claim-size thresholds, with numbers

Claim-size thresholds are the least understood rule. They look simple and behave in surprising ways.

New York's $2,000 line is a floor on aggregate property damage. Under the 2010 amendment to Insurance Law section 2335, as DFS describes it, an insurer cannot raise your premium solely because of an accident that did not produce more than $2,000 in aggregate property damage, although more than one accident in the experience period can still support a surcharge. Chapter 277 of 2010 took effect on November 27, 2010, for policies entered into, modified or renewed on or after that date.

Pennsylvania's line is different in design: it is a cap on the three-year total of your claim costs above any deductible, not a per-claim test. The Pennsylvania Insurance Department raised it to $2,350 from July 1, 2026. The notice says the department must revisit the figure at least every three years using price indexes for medical care and auto maintenance and repair.

California's $1,000 test applies to deciding fault for accidents without injury.

Here is a worked example. The numbers are made up to show the mechanics, not market data.

Say a Pennsylvania driver has one claim, and the insurer paid $2,100 beyond the deductible. That total is under the $2,350 threshold, so the insurer may not apply a surcharge, rate penalty or point for it. Now say the same driver has a second claim two years later, for $800. The three-year aggregate is $2,900, which exceeds the threshold, and the insurer may then consider surcharging. The first claim, which was protected on its own, now counts toward the total.

Now the New York version. A driver is hit while merging, is found at fault and the other car's repair totals $1,700, with no injuries. That is below $2,000, so the accident alone cannot raise the premium. If the repair were $2,400, the insurer could surcharge under its filed rule, and DFS says the amount would not depend on the claim size.

This is why a study that defines its accident as "$2,000 or more in damage" is a loose test. A claim of $2,100 is surchargeable in New York and, under the 2026 threshold, protected in Pennsylvania. The same label produces opposite outcomes, and the study's state ranking partly reflects that.

How accident forgiveness changes the result

Accident forgiveness is a rating-plan feature that keeps the first at-fault accident from raising your rate. It is not a legal right and it is not uniform. Each insurer defines eligibility, cost and exclusions, and availability varies by state. Progressive's public explainer is a good illustration of how one carrier structures it. As of November 2026, it describes three layers: a free "small" forgiveness for a first claim of $500 or less for new customers in most states, a free "large" forgiveness for customers of at least five years with an accident- and violation-free record, and a purchasable benefit that forgives one eligible accident per policy period, not available in all states. See Progressive's accident forgiveness page. Other insurers use different terms.

Three practical effects for the surcharge comparison:

• A quote study that adds an accident to a clean driver may not capture forgiveness, because forgiveness depends on tenure with the insurer that a new-quote panel does not have. The study may overstate the increase for a long-tenured customer with forgiveness, and fairly states it for a new customer shopping.
• Forgiveness often waives the surcharge but may not protect every discount. Read whether a claim-free or similar discount is still lost. The accident forgiveness explained guide covers these details, and accident forgiveness and disappearing deductibles: are they worth it? weighs whether it is worth buying.
• Forgiveness applies to the insurer that sold it. If you switch carriers after an accident, the new company sees the accident on your record (see claims history and the CLUE report) and prices from scratch.

Why aggregate figures deserve distrust

A headline such as "an accident costs you 45%" blends many different situations. Four problems make aggregates unreliable for any individual decision.

1. They average across states with opposite rules. A national mean mixes a 16.5% state with a 70.7% state. No driver lives in the average.
2. They average a specific accident. The accident type, claim size and fault share vary, and the studies choose one.
3. They are quotes for new customers. Renewal surcharges can differ from new-business surcharges, and a long-time customer can have forgiveness or tenure credits.
4. They are snapshots. Insurers revise surcharge rules in rate filings, and market conditions change quickly. A figure from one year can be stale the next. See fact-checking car insurance headlines about percent increases for how to read a percent claim.

For a practical read of rate studies in general, see how to read car insurance rate studies and average-cost claims.

How to estimate your own surcharge

You do not need a study. You need three pieces of information, and you can get them in an afternoon.

1. Find the rule in your state. Check the state insurance department's consumer pages for thresholds, fault standards and surcharge caps. The state car insurance requirements lookup is a starting point for the basics.
2. Get the insurer's own number. Ask your current insurer, or a prospective one, what the surcharge schedule says for a first at-fault accident with your claim size. Insurers file their rating rules with state regulators in most states, so the company should be able to give you an answer.
3. Run the dollar comparison. Compare the surcharge across the number of years it applies. Then use the Should I file a claim? calculator before you decide whether to file at all, particularly for a claim near a threshold.

Questions to ask your insurer or agent:

• "If I file a claim for about this amount and am found at fault, what happens to my premium, in dollars, at the next renewal?"
• "Is the surcharge a percentage, a tier change, or points? How long does it last?"
• "Do I lose any discount, such as a claim-free or good-driver discount, in addition to the surcharge?"
• "Do I have accident forgiveness, and does it apply to a claim of this size?"
• "Is there a dollar threshold under which a claim is not surcharged in this state?"
• "Will the surcharge differ if I am found 50% at fault rather than more than 50%?"

If a renewal notice shows a jump you cannot explain, the renewal rate increase checker helps you sort out what part came from the accident and what came from rate changes affecting everyone. See can a not-at-fault accident raise your premium? if the accident was not your fault.

Common questions

Can my rate go up after an accident that was not my fault?

In many places the surcharge should not apply, but your rate can still change for reasons unrelated to the accident. New York's DFS says it does not read the law as allowing a surcharge on an insured who was not at fault, and Georgia and Delaware have rules that bar it in the circumstances described above. Fault, however, is decided by the insurer first, and disputes about it can take work.

If I pay the other driver out of pocket, can I avoid the surcharge?

Sometimes, but the rules and practices differ, and paying privately can create other problems: the other driver may later file a claim anyway, your policy may require you to report accidents promptly, and injuries can surface later. Ask your insurer how a self-paid incident that is never reported will be treated before relying on that approach.

How long does the surcharge last?

It varies by insurer and state. Delaware's regulation, for instance, caps the surcharge at three years from when it was first imposed. Elsewhere the insurer's filed rule and the state's limits determine the period. Your declarations page and renewal notice show what is currently applied.

Should I trust a state ranking from a quote study?

Use it as a rough orientation, not as a promise. The rankings tell you that spreads are large and that the effect is not uniform. They do not tell you your own number, because your insurer, claim size, tenure and discounts all differ from the sample.

Key takeaways

• The "about 40 percent" figure is a national blend of very different state results. A 2026 quote study found 45.0% nationally, with states from 16.5% to 70.7%, and another study with a different driver found about 60%.
• Percent and dollars tell different stories: New Hampshire ranks third in percent but is below average in dollars, while Arizona has the largest dollar increase.
• Some states limit surcharges by fault, by dollar threshold or by cap. New York, Pennsylvania, Delaware, Georgia and Florida are documented examples, and your state may have its own rule.
• Quote studies use one sample driver and one accident definition, so they cannot reproduce your situation. Ask your insurer for its filed surcharge in dollars and whether you have accident forgiveness.
• Rules and rates change. Everything above reflects sources read in November 2026; verify your state's current rule with its insurance department.