6.4 Part C Uninsured/Underinsured Motorists

The Gap Part C Fills

Even with compulsory insurance laws, many at-fault drivers cannot pay. The Insurance Research Council (2023) estimated that roughly 14-15% of U.S. drivers are uninsured, and a larger share are underinsured. Part C - Uninsured Motorists (UM) coverage pays the insured for bodily injury (and, where elected, property damage) caused by an at-fault driver who has no liability insurance. Underinsured Motorists (UIM) coverage applies when the at-fault driver has insurance but not enough to pay the insured's damages.

Part C is first-party coverage but it behaves like third-party recovery: the insured must be legally entitled to recover from the other driver - meaning the other driver must be at fault. If the insured is the at-fault party, Part C does not respond.

Uninsured vs. Underinsured Definitions

A hit-and-run ("phantom vehicle") that injures the insured and flees triggers UM, not Part A or Part D. Many states require physical contact for a hit-and-run UM claim, or independent corroboration if no contact occurred - a frequently tested nuance.

How UIM Pays: Reduction vs. Add-On (Worked Numerics)

States use one of two methods to calculate UIM, and exam questions hinge on which applies.

Difference (reduction) method - the majority rule: UIM pays the insured's UIM limit minus what the at-fault driver's liability already paid.

Worked example: Insured's damages = $100,000. At-fault driver's liability limit = $25,000 (paid in full). Insured's UIM limit = $100,000. UIM pays $100,000 - $25,000 = $75,000. Total recovery = $25,000 + $75,000 = $100,000.

Add-on (excess) method - a minority of states: UIM stacks on top of the at-fault limit up to the UIM limit. Same facts: insured collects $25,000 + the full $100,000 UIM = up to $125,000 (capped at actual damages of $100,000, so $100,000).

Consent-to-Settle, Stacking, and Offers

Three exam-critical conditions:

• Consent to settle / subrogation: Before settling with the at-fault driver, the insured pursuing UM/UIM should obtain the UM/UIM insurer's written consent. Settling and signing a release without consent can destroy the insurer's subrogation rights and forfeit the UM/UIM claim.
• Stacking: In some states an insured with multiple vehicles or policies may stack (add together) UM/UIM limits across vehicles; many policies and states prohibit anti-stacking clauses or allow waivers.
• Mandatory offer: Insurers must offer UM/UIM coverage; an insured who declines must usually do so in writing. UM bodily injury is commonly mandatory in most states even when UIM is optional.

Remember the hierarchy: Part A pays others; Part B pays the insured's medical regardless of fault; Part C pays the insured when someone else is at fault but uninsured/underinsured.

UM vs. UIM: The Core Distinction

Uninsured Motorists (UM) pays when the at-fault driver has no liability insurance, is unidentified (hit-and-run with contact, in most states), or whose insurer is insolvent. Underinsured Motorists (UIM) pays when the at-fault driver has insurance but insufficient limits to cover your injuries. UM/UIM is first-party coverage that responds to your damages for bodily injury (and, in some states, property damage).

UIM Worked Example and the Trigger

You carry $100,000 UIM. The at-fault driver carries only $50,000 liability, and your damages are $90,000. UIM is triggered because the other driver's $50,000 is less than your need. Under the common difference (excess) method, you collect $50,000 from the at-fault carrier and your UIM pays the $40,000 gap up to your $100,000 limit. Note many states (including Minnesota) require insurers to offer UM/UIM and require written rejection to waive it — a frequent state-portion crossover point.

Stacking and the "Phantom Vehicle" Rule

Two more UM/UIM points recur. Stacking allows an insured with multiple covered autos (or multiple policies) to add the UM/UIM limits together in some states, multiplying available coverage; other states and policy language prohibit stacking. For hit-and-run (phantom vehicle) UM claims, most states require physical contact with the unidentified vehicle (or independent corroboration) to prevent fraudulent "a car ran me off the road" claims.

Limits Offer Requirement

States typically require insurers to offer UM/UIM at limits equal to the liability limit; the insured must reject in writing to take lower limits or none. A producer who fails to document that rejection invites an E&O claim — tying this national concept to the state and ethics portions.

Arbitration and the Exhaustion Requirement

UM/UIM disputes over fault or amount are commonly resolved by arbitration under the policy. For UIM, most policies require the insured to first exhaust the at-fault driver's liability limits (or obtain the insurer's consent to settle) before UIM pays, protecting the UIM insurer's subrogation rights against the underinsured driver. Settling with the at-fault carrier without consent can forfeit UIM coverage — a trap the exam uses to test whether you understand the exhaustion-and-consent sequence.