What car insurance does and why states require it

Car insurance is a contract between you and an insurance company. You pay a premium — usually monthly or every six months — and the company agrees to pay for certain costs if you cause an accident, your car is damaged or stolen, or someone is injured. Every state except New Hampshire requires you to carry at least a minimum amount of liability coverage before you can legally drive on public roads.

Liability coverage is the foundation. It pays for damage or injuries you cause to someone else — their car, their medical bills, their property. It does not pay for your own damage. States set minimum liability limits, but those minimums are often low. In many states, the minimum is $25,000 per person and $50,000 per accident for bodily injury, plus $25,000 for property damage. If you cause an accident that exceeds those limits, you are personally responsible for the rest.

Insurance companies use several factors to set your premium: your age, driving record, the type of car you drive, how much you drive, where you live, and your credit score. Younger drivers and those with accidents or traffic violations typically pay more. A sports car costs more to insure than a sedan. Someone who drives 50 miles a day pays more than someone who drives 5 miles a day.

Key Takeaways

  • Liability coverage is legally required in every state except New Hampshire and pays for damage or injuries you cause to others, not to yourself.
  • Collision and comprehensive coverage protect your own car but are optional; collision covers accidents and comprehensive covers theft, weather, and vandalism.
  • Deductibles — the amount you pay out of pocket before insurance kicks in — directly affect your premium; higher deductibles mean lower monthly costs.
  • Your premium depends on your age, driving history, the car itself, how much you drive, and where you live, and these factors vary significantly between insurance companies.
  • Shopping around and bundling policies with the same insurer often saves money, and many insurers offer discounts for good driving, safety features, or paying in full.

Liability coverage: what it covers and what it does not

Liability coverage has two parts: bodily injury liability and property damage liability. Bodily injury liability pays for medical expenses, lost wages, and pain and suffering if you injure someone in an accident you cause. Property damage liability pays to repair or replace their car or other property you damage. When you see a policy written as "25/50/25," that means $25,000 bodily injury per person, $50,000 bodily injury per accident, and $25,000 property damage.

Liability does not cover your own injuries or your own car's damage, even if you cause the accident. It also does not cover medical payments or lost wages for you and your passengers — that is what medical payments coverage does, and it is optional. Liability also does not cover uninsured or underinsured drivers who hit you; that is uninsured motorist coverage, which is required in some states and optional in others.

If you cause an accident and the damages exceed your liability limits, the injured party can sue you personally. They can go after your wages, your bank accounts, and your assets. This is why many financial advisors recommend carrying limits higher than your state's minimum — often $100,000 per person and $300,000 per accident — or adding an umbrella policy for extra protection.

Collision and comprehensive: protecting your own car

Collision coverage pays to repair or replace your car if you hit another vehicle, a tree, a guardrail, or any other object. It covers accidents you cause and accidents caused by someone else. Comprehensive coverage pays for damage from events you cannot control: theft, vandalism, weather (hail, flooding, wind), animal strikes, and falling objects. Neither collision nor comprehensive is legally required, but if you have a car loan or lease, your lender almost always requires you to carry both.

Both collision and comprehensive come with a deductible — the amount you pay out of pocket before the insurance company pays the rest. A $500 deductible means you pay $500 and insurance pays the rest. A $1,000 deductible means you pay $1,000. Higher deductibles lower your monthly premium. If your car is worth $8,000 and you have a $1,000 deductible, paying $50 more per month for a $500 deductible might not make financial sense — you are paying extra to protect against a loss you could absorb. If your car is worth $25,000, the math shifts.

Collision and comprehensive claims do not affect your liability limits. If you file a collision claim, you still have the same liability coverage for anyone else you injure. The two are separate buckets of money.

Uninsured and underinsured motorist coverage

Uninsured motorist coverage (UM) pays for your injuries and car damage if you are hit by a driver with no insurance. Underinsured motorist coverage (UIM) pays the difference if you are hit by a driver whose liability limits are too low to cover your damages. In some states, UM and UIM are required; in others, they are optional but recommended. The coverage limits for UM and UIM are often the same as your bodily injury liability limits, but you can usually choose different amounts.

These coverages protect you against a real risk: roughly 13 percent of drivers nationwide carry no insurance, and that percentage is higher in some states and regions. If an uninsured driver hits you and causes $15,000 in damage, your collision coverage would pay (minus your deductible), but if you do not have collision, you have no recovery unless you sue the driver — and if they have no insurance, they likely have no money to collect from.

UM and UIM are relatively inexpensive add-ons, usually a few dollars per month. Many insurance companies automatically include them at your state's minimum liability limits unless you decline in writing.

Medical payments coverage and personal injury protection

Medical payments coverage (MedPay) pays for reasonable medical expenses for you and your passengers after an accident, regardless of who caused it. It covers ambulance fees, hospital bills, surgery, dental work, and sometimes funeral expenses. It does not cover lost wages or pain and suffering. The coverage limit is usually $1,000 to $5,000 per person. MedPay is optional in most states.

Personal injury protection (PIP) is similar but broader and is required in some states (called "no-fault" states). PIP covers medical expenses, lost wages, and sometimes childcare or household services if you cannot work because of accident injuries. PIP limits are usually higher than MedPay — often $10,000 to $25,000 — and the coverage is more comprehensive. In no-fault states, PIP is mandatory; in other states, it is optional.

MedPay and PIP overlap with your health insurance. If you have health insurance, your health plan will likely pay your medical bills first, and MedPay or PIP pays what your health plan does not cover. This is called coordination of benefits. If you do not have health insurance, MedPay or PIP becomes more valuable because it is your only source of payment for accident-related medical costs.

How deductibles, premiums, and discounts interact

Your deductible choice directly affects your premium. A $250 deductible costs more per month than a $1,000 deductible because the insurance company is taking on more risk. The trade-off is between predictable monthly costs and out-of-pocket costs if you have a claim. If you rarely have accidents and can afford to pay $1,000 out of pocket, a higher deductible saves money over time. If you are worried about affording a large unexpected expense, a lower deductible costs more monthly but protects you.

Insurance companies offer discounts that can significantly reduce your premium. Common discounts include: good driver discounts (usually 5 to 15 percent for three to five years without accidents or violations), bundling (combining auto and home insurance with the same company, often 10 to 25 percent), paying in full instead of monthly (2 to 5 percent), safety features on your car (anti-theft devices, airbags, automatic braking), completing a defensive driving course (5 to 10 percent), and low mileage (if you drive under a certain threshold, sometimes 5 to 15 percent). Some insurers offer usage-based programs where they monitor your driving through an app and give discounts for safe habits.

The same coverage from two different insurers can cost very different amounts. A 25-year-old with one speeding ticket might pay $1,200 per year with one company and $900 with another for identical coverage. Shopping around — getting quotes from at least three insurers — is the most direct way to lower your premium. Many insurers offer online quote tools that take 10 to 15 minutes and do not require a phone call.

What happens when you file a claim

If you are in an accident, contact your insurance company as soon as possible — most policies require you to report within a specific timeframe, often 24 to 72 hours. Provide the date, time, location, and description of what happened. If another vehicle was involved, exchange name, phone number, address, driver's license number, license plate, and insurance information with the other driver. Take photos of all vehicle damage, the accident scene, and any visible injuries. If police responded, get the report number.

Your insurance company will assign a claims adjuster who will contact you to gather more details. The adjuster may request a recorded statement, inspect your car, and review police reports or medical records. The adjuster's job is to determine whether the claim is covered under your policy and, if so, how much the company will pay. This process typically takes one to four weeks for straightforward claims and longer for complex ones.

If you disagree with the adjuster's decision — for example, if they deny your claim or offer less money than you think your car is worth — you have options. You can request a review by a supervisor, hire an independent appraiser to assess your car's value, or file a complaint with your state's insurance commissioner. Many states also have mediation or arbitration processes for disputes.

Frequently Asked Questions

Do I need collision and comprehensive if my car is paid off?

No, they are not legally required. However, if your car is worth more than you could afford to replace out of pocket, collision and comprehensive protect you against that loss. If your car is older and worth $3,000, paying $100 per month for collision and comprehensive may not make financial sense. If it is worth $20,000, it probably does.

What is the difference between actual cash value and agreed value?

Actual cash value is what your car is worth at the time of loss, accounting for depreciation. If your five-year-old car is worth $12,000 and is totaled, the insurance company pays $12,000 minus your deductible. Agreed value means you and the insurer agree on the car's value upfront, usually for classic or collectible cars. If it is totaled, you get that agreed amount regardless of market value at the time of loss.

Can my insurance company drop me after an accident?

Insurance companies can choose not to renew your policy when it expires, but most states prohibit them from canceling mid-term because of a single accident. After renewal, if you have multiple accidents or violations, the company can decline to renew. If you are dropped, your state's insurance commissioner can direct you to an insurer of last resort, which is required to cover you at a higher premium.

Does my insurance follow me or the car?

Your insurance follows the car, not the driver. If you lend your car to a friend and they cause an accident, your insurance pays (up to your liability limits), and your rates may increase. The friend's insurance is secondary. This is why it is important to know who is driving your car and to have adequate liability limits.

How long do accidents and violations stay on my driving record?

This varies by state. Most accidents stay on your record for three to five years and violations for three to seven years, though serious violations like DUI can stay longer. Insurance companies use this history to set rates, so an accident from five years ago may no longer affect your premium, but one from two years ago likely will.