What the Numbers Mean: 100/300/100 Decoded

A liability limit like 100/300/100 looks like a code, but it’s just three separate dollar caps stacked together. Per the Insurance Information Institute, liability coverage pays for the other driver’s injuries and property damage when you’re found at fault — and the three numbers set the ceiling on each piece.

Here’s why the middle number matters: say you’re at fault in a crash that seriously injures two people. If your per-person limit is $25,000 and one person’s hospital stay and rehab run well past that, your insurer stops paying at the limit — and you’re personally on the hook for the rest. This is an illustrative example, not a quoted bill, but it’s the exact math that catches drivers with low limits. A modern car is also expensive to total or repair, so a thin property-damage number can run out fast too.

One correction worth making early: 100/300/100 is not “full coverage.” These three numbers are liability limits only — they pay for the other person’s losses when you’re at fault. “Full coverage” is an informal term for liability plus collision and comprehensive, which protect your own car. If you’re weighing that decision, AdvoraHQ’s guide to full coverage vs. liability breaks down which one you actually need.

How does 100/300 compare with 250/500, the next tier up? The structure is identical — per-person / per-accident bodily injury — just doubled: $250,000 per person and $500,000 per accident, usually paired with more property-damage coverage too. 100/300/100 is the recommended car insurance coverage for a typical driver with some savings or home equity; 250/500 territory is for people with meaningfully more to protect, covered in the net-worth section below. Either way, the real question of what car insurance coverage you should have comes down to what you’d stand to lose, not just what sounds impressive on a quote.

Is the State Minimum Enough? (Usually Not)

Every state (other than New Hampshire) sets a minimum liability requirement, and it’s tempting to treat “legal” as “adequate.” It usually isn’t. State minimums were set as a legal floor — the least you’re allowed to carry — not a considered estimate of what a real accident costs. Many states still require limits like 25/50/25, and some are lower still, even as medical bills and vehicle repair costs have climbed for years. A handful of states set their floor higher, closer to 50/100/50 — better than 25/50/25, but still worth checking against the 100/300/100 baseline below rather than assuming it’s automatically enough.

In plain terms, here’s why state minimum car insurance is a bad deal for most drivers: it’s priced to be cheap and legal, not to actually cover a serious crash. You end up paying the smallest possible premium in exchange for carrying the largest possible personal risk — the opposite of what insurance is supposed to do.

Your state’s exact minimum is worth knowing, and it changes from time to time — check it directly with your state’s Department of Insurance rather than relying on a number you saw once. But treat whatever figure you find as a starting floor to build above, not a target to land on.

How Much Liability Do You Need to Protect Your Assets?

Once you accept that the minimum probably isn’t enough, the next question is simple: enough for what? A useful rule of thumb, echoed by Consumer Reports and the III, is to carry liability coverage that roughly matches what you could lose in a lawsuit — your net worth: home equity, savings, and investments combined.

The good news: raising your limits usually costs less than people expect. Insurers price the first dollars of coverage the most heavily, so moving from a lower limit like 50/100 up to 100/300 is often a modest add to the premium relative to the protection it buys — you’re not doubling your bill to double your bodily-injury protection. See AdvoraHQ’s breakdown of average monthly car insurance costs for how pricing actually works.

If your net worth is high enough that even 250/500/100 wouldn’t fully cover a worst-case judgment, the next layer isn’t a bigger auto policy — it’s an umbrella policy, which sits above your auto and home liability limits for large claims. AdvoraHQ’s guide to umbrella insurance covers how that layer works and who tends to need it.

Do You Need Uninsured Motorist Coverage? (Even With Health Insurance)

Should you get uninsured motorist coverage? For most drivers, yes. And is uninsured motorist coverage worth it for the price? Also generally yes — it’s one of the cheaper add-ons on a policy relative to the protection it buys, because roughly one in seven drivers on the road carries no insurance at all.

Liability coverage protects other people when you’re at fault. Uninsured motorist (UM) coverage flips that: it protects you when someone else causes the crash and doesn’t have insurance to pay for it. Underinsured motorist (UIM) coverage fills the gap when the other driver has some insurance, just not enough. Uninsured motorist property damage (UMPD) covers your car specifically — whether it’s required varies by state; some make it mandatory, others offer it as an option, and a few don’t offer it at all, so it’s worth confirming with your own state’s rules.

In states that allow it, stacked UM coverage lets you combine the UM limits across multiple vehicles on the same policy, which can meaningfully raise your total protection at a modest added cost. And according to the National Association of Insurance Commissioners, a hit-and-run driver is generally treated as an uninsured driver for claims purposes — so yes, UM coverage typically responds to a hit-and-run, subject to your state’s specific rules.

So, do you need medical payments coverage if you have health insurance? Often yes, in a smaller supporting role: MedPay is inexpensive, doesn’t get reduced for fault, and typically covers the deductibles and copays your health plan leaves you holding — plus it extends to passengers who may not have your health coverage at all.

If you’ve already been in an accident and you’re trying to figure out what a claim covers or how to deal with the other driver’s insurer, that’s a separate topic from choosing coverage up front — worth raising directly with your insurance company or a licensed agent.

When to Drop Collision and Comprehensive (The 10% Rule)

Collision covers damage to your own car in a crash. Comprehensive covers theft, weather, animal strikes, and vandalism. Both are optional once you own the car outright — but that doesn’t mean you should always drop them.

A widely used guideline, discussed by outlets like Forbes Advisor, is the 10% rule: if the annual cost of collision and comprehensive together runs at roughly 10% or more of your car’s current value, it may make more financial sense to drop them. The logic is simple — the most your insurer will ever pay out is the car’s depreciated value minus your deductible, so once the premium approaches that ceiling, you’re paying a lot for a shrinking payout. It’s a rule of thumb, not a law, and it’s worth weighing against how much cash you’d have on hand to replace the car if something happened to it.

One firm exception: if the car is financed or leased, you usually can’t drop these coverages. Lenders and lessors require collision and comprehensive — and sometimes gap coverage — for as long as they have a financial stake in the vehicle. Once it’s paid off, the decision is entirely yours. And if you’re weighing collision/comprehensive against other ways to bring your bill down, AdvoraHQ’s guide to lowering your car insurance covers additional savings that don’t involve giving up coverage.

Frequently Asked Questions

How much car insurance do I need?

Most drivers need more than their state’s legal minimum. A common baseline is 100/300/100 in liability coverage, sized upward if you have significant assets to protect, plus uninsured motorist coverage.

What does 100/300/100 mean?

$100,000 in bodily injury coverage per person, $300,000 in bodily injury coverage per accident (combined across everyone hurt), and $100,000 in property damage coverage.

Is 100/300/100 full coverage?

No. It’s a liability limit. “Full coverage” informally means liability plus collision and comprehensive, which protect your own vehicle.

Is the state minimum car insurance enough?

Usually not. State minimums are legal floors, and a single serious accident can exceed them, leaving you personally responsible for the difference.

How much liability insurance do I need to protect my assets?

A common approach is to size your liability limits to roughly match your net worth — your savings, investments, and home equity — since a judgment above your limits can reach those assets.

What’s the difference between 100/300 and 250/500?

Both describe bodily injury limits (per person / per accident). 250/500 offers more than double the protection of 100/300 and is often paired with a higher property-damage limit for drivers with more assets to protect.

Do I need uninsured motorist coverage if I already have health insurance?

Yes, in most cases. Health insurance doesn’t cover your car’s damage, the other driver’s costs, your lost wages, or pain and suffering — gaps that uninsured and underinsured motorist coverage are built to fill.

Does uninsured motorist coverage cover a hit-and-run?

Generally yes. An unidentified hit-and-run driver is typically treated as an uninsured driver for claims purposes, subject to your state’s rules.

What is stacked uninsured motorist coverage?

In states that allow it, stacking lets you combine the UM limits across multiple vehicles on one policy to reach a higher total limit.

Do I need collision coverage on an old car?

Not necessarily. If the car is paid off and the annual cost of collision and comprehensive approaches roughly 10% or more of the car’s value, many drivers choose to drop it.

What coverage does a lender require on a financed car?

Lenders and lessors typically require collision and comprehensive coverage, and sometimes gap coverage, for as long as they have a financial interest in the vehicle.

Does raising my liability limits cost a lot more?

Usually not proportionally. Because the first dollars of coverage are priced the most heavily, moving from a low limit up to something like 100/300 is often a modest increase relative to the added protection.