Part C Uninsured/Underinsured Motorists

The Part C promise

Part C - Uninsured/Underinsured Motorists pays damages a covered person is legally entitled to recover from the owner or operator of an uninsured or underinsured motor vehicle, for bodily injury caused by an accident. Some states add property damage UM, but the bedrock is BI.

The phrase legally entitled to recover is critical: unlike Part B (pure no-fault), Part C requires that the other driver be at fault. The insured's own insurer steps into the shoes of the absent or inadequate at-fault insurer. It is first-party coverage (paid by the insured's own policy) that nonetheless turns on third-party fault.

What counts as 'uninsured'

An uninsured motor vehicle under Part C includes:

• A vehicle with no bodily injury liability insurance at the time of the accident.
• A vehicle whose insurer denies coverage or becomes insolvent.
• A hit-and-run vehicle whose driver and owner cannot be identified (the 'phantom' vehicle) that hits the insured, the insured's covered auto, or a vehicle the insured occupies.

An uninsured vehicle does not include a vehicle owned by or furnished for the regular use of the named insured/family member, a self-insured vehicle, or a government-owned vehicle (these are common exclusions).

Underinsured motorist (UIM)

A vehicle is underinsured when it carries some liability insurance, but the limits are lower than the injured insured's damages (and, depending on the state, lower than the insured's own UIM limit). UIM fills the gap between what the at-fault driver's policy pays and the insured's covered losses, up to the UIM limit.

Most states use a difference-in-limits method: the insured's UIM limit applies as the ceiling, and the insurer pays the insured's UIM limit minus the amount recovered from the at-fault driver. A minority use an excess (add-on) method, but the exam usually tests difference-in-limits.

Worked UIM example (difference in limits)

An insured carries UIM of $100,000 per person. She suffers $130,000 in proven bodily injury damages. The at-fault driver carries only $25,000 per-person BI liability, which his insurer pays in full.

• At-fault driver pays: $25,000.
• Insured's UIM limit: $100,000.
• UIM pays = UIM limit minus amount recovered = $100,000 - $25,000 = $75,000.
• Total recovered by insured = $25,000 + $75,000 = $100,000.

Her damages were $130,000, so $30,000 stays uncompensated because total recovery is capped at her UIM limit. To collect more, she would have needed a higher UIM limit. (Under an excess/add-on state, UIM would pay the full $100,000 on top of the $25,000 - know which method your state uses.)

Offer, rejection, and arbitration

UM/UIM is consumer-protective coverage:

• Insurers must generally offer UM/UIM at limits equal to the policy's liability limits; the insured can select lower limits or reject the coverage only by a written waiver.
• Disputes over whether the insured is legally entitled to recover, or over the amount, are commonly resolved by arbitration under the policy.
• The insured must not settle with the at-fault party without the UM/UIM insurer's consent, because that can destroy the insurer's subrogation rights against the at-fault driver.

The written-rejection rule and the consent-to-settle/subrogation trap are both frequently tested.

UM vs. UIM at a Glance

UM/UIM pays damages the insured is legally entitled to recover from the at-fault party — meaning the insured must prove the other driver's fault and the amount, just as in a lawsuit. It does not pay for the insured's own at-fault accidents (that is liability/MedPay/collision).

Property Damage and Stacking

Some states offer UMPD (uninsured-motorist property damage) for vehicle repair when an uninsured driver is at fault, sometimes with a deductible. Stacking — combining UM limits across multiple vehicles on one policy — is permitted in some states and barred by anti-stacking language in others; whether stacking applies is a state-law question the exam flags rather than assumes.

Worked UIM "Difference-in-Limits" Example

An insured carries $100,000 UIM. She suffers $130,000 in damages from a driver carrying only $25,000 liability. Under the common reduction (offset) approach, UIM pays the difference between her UIM limit and what she collected from the at-fault driver: $100,000 − $25,000 = $75,000 UIM, for a total recovery of $100,000, leaving $30,000 uncompensated. Under an excess/add-on state, UIM pays the full $100,000 on top of the $25,000 = $125,000, leaving only $5,000 uncovered. Knowing which method a state uses changes the dollar answer — the exam usually flags it.

Consent-to-Settle Trap

The insured must not settle with (and release) the at-fault driver without the UM/UIM insurer's consent, because a release destroys the insurer's subrogation right against that driver. Settling first can forfeit UIM coverage. This consent-to-settle/subrogation pairing is a favorite forfeiture question.

Hit-and-Run and "Phantom Vehicle" Rules

A hit-and-run driver is treated as uninsured, so UM responds — but most states require physical contact (or independent corroboration) to guard against fraudulent "phantom vehicle" claims where a driver swerves and crashes alleging an unidentified car. Knowing that UM covers hit-and-run, subject to the contact/corroboration requirement, is a frequent question.

Stacking and Anti-Stacking

Where permitted, stacking combines UM/UIM limits across multiple insured vehicles (two cars at $50k each = $100k available) or across policies; many states and policies bar it with anti-stacking language. Whether stacking applies is a state-law issue the exam flags rather than assumes. Colorado, for example, addresses stacking by statute, so the safe exam approach is to read whether the question states stacking is allowed.