Last Updated on December 29, 2025

Uninsured motorist bodily injury (UMBI) is optional (or required, depending on your state) auto insurance that helps pay for injury-related costs when the at-fault driver has no liability insurance—or when the driver can’t be identified in certain situations, like many hit-and-run accidents.

UMBI matters because uninsured driving is still common. Recent industry estimates put the U.S. uninsured motorist rate at about 15% (roughly 1 in 7 drivers), and it varies widely by state. See the latest uninsured driver estimates here: uninsured drivers by state.

If an uninsured driver injures you, they’re still legally responsible—but collecting can be tough. UMBI exists so you’re not forced to rely on the at-fault driver’s ability to pay.

Key Takeaways

• UMBI pays for injury-related losses (medical care, lost wages, and more) when an at-fault driver has no insurance—or qualifies as unknown in certain hit-and-run situations.
• It generally does not pay for vehicle damage; that’s typically handled by collision coverage or uninsured motorist property damage (UMPD), depending on your state and policy.
• UMBI limits are usually shown per person/per accident (like 50/100), and the best limit is often similar to your liability limits.
• UMBI is required in some states and optional in others, and it often costs only a few dollars per month for modest limits—though pricing depends heavily on your state, limits, and ZIP code.

What Is UMBI Coverage?

UMBI is a type of uninsured motorist coverage that pays for bodily injury losses after an accident caused by an uninsured (or sometimes unidentified) driver. Depending on your state and policy language, it may also apply if you’re hit while walking or biking—if the crash involves a vehicle and the at-fault party qualifies as uninsured/unknown.

UMBI is different from uninsured motorist property damage, which is designed to pay for damage to your car or other property. If you’re looking for the property-damage side, see uninsured motorist property damage coverage (UMPD).

What Does UMBI Cover?

UMBI is built to cover the financial fallout of injuries after a crash with an uninsured driver. Coverage typically includes:

• Medical treatment (ER care, imaging, surgery, hospital stays, follow-up visits, etc.)—often the same categories you’d expect when car insurance pays for medical bills after an accident.
• Lost wages if injuries keep you from working.
• Pain and suffering (availability and how it’s calculated varies by state and policy).
• Funeral expenses in fatal accidents (policy/state rules vary).

What UMBI Usually Does Not Cover

UMBI is not “everything coverage.” Common limitations include:

• Damage to your vehicle (that’s generally UMPD, collision coverage, or the other driver’s liability insurance).
• Your own at-fault injuries if you caused the crash (UMBI is triggered by an uninsured/unknown at-fault driver).
• Injuries above your policy limits (UMBI pays up to the limit you selected).
• Some hit-and-run scenarios if you don’t report promptly or can’t meet your policy’s requirements (for example, documenting the crash and cooperating with the investigation).

UMBI vs. Underinsured Motorist Bodily Injury

UMBI applies when the at-fault driver has no insurance (or qualifies as unknown/uninsured under your policy). Underinsured motorist bodily injury (UIMBI) applies when the at-fault driver has insurance, but their limits are too low to cover your injuries. Here’s a deeper breakdown of the difference between uninsured and underinsured motorist coverage.

How Do UMBI Limits Work?

UMBI limits are usually shown as two numbers, such as 50/100:

• $50,000 per person: the most the policy will pay for one injured person.
• $100,000 per accident: the total the policy will pay for everyone injured in the same crash.

Example: If three people are injured and each has $60,000 in medical bills and related losses, a 50/100 UMBI limit would typically pay up to $50,000 per person, capped at $100,000 total for the accident.

Who Does UMBI Protect?

UMBI commonly protects you and members of your household when you’re driving, riding in a covered vehicle, or sometimes even when you’re a pedestrian. It can also protect passengers in your vehicle in many situations—details depend on state law and your policy wording.

Is UMBI Required?

State rules vary. In some states, uninsured motorist coverage is mandatory. In many other states, insurers must offer it, but you can reject it (often by signing a waiver). The easiest way to confirm what your state requires is to check your state’s minimum coverage rules: state-by-state auto insurance requirements.

How Much Does UMBI Cost?

UMBI is usually one of the more affordable add-ons on an auto policy, but pricing varies a lot by state, limits, and risk. As a rough benchmark, many drivers pay only a few dollars per month for modest uninsured motorist limits (for example, minimum-style limits like 25/50), while higher limits can cost more.

Your cost is most influenced by:

• Your UMBI limit (higher limits typically cost more).
• Uninsured driver rates where you live (higher uninsured rates often mean higher UMBI premiums).
• Stacking rules (if your state/policy allows stacking, it can affect price).
• Your driving and claims profile (and your vehicle/usage).
• Location—rates can change dramatically even within the same state based on your ZIP code.

How to File a UMBI Claim

Filing a UMBI claim is similar to filing any other auto claim, but documentation matters (especially for hit-and-run cases). In general:

• Call 911 and get medical help if anyone is injured.
• Report the crash and get a police report number (this is often critical when the other driver is unknown).
• Collect evidence (photos, witness info, dashcam video, scene details).
• Notify your insurer promptly and ask what documentation they need.
• Track medical treatment and wage loss with bills, notes, and employer verification.

Some drivers worry that using uninsured motorist coverage will automatically increase premiums. That’s not always true—rules vary by state and insurer, and “not-at-fault” claims are often treated differently. Here’s a detailed explanation: do uninsured motorist claims raise your rates?

How Much UMBI Coverage Should You Get?

A common approach is to choose UMBI limits that are similar to your liability limits. If you carry higher liability limits to protect others, it often makes sense to protect yourself at a similar level—especially because serious injuries can get expensive quickly.

Not sure where to start? Here’s a practical guide to choosing policy limits: what auto insurance limits should I have?

FAQs on UMBI Coverage

Final Word

UMBI helps pay for medical care, lost income, and other injury-related losses after an accident caused by an uninsured (or sometimes unidentified) driver. Because uninsured driving is still common, UMBI can be a relatively low-cost way to protect yourself from a worst-case scenario.