6.4 Part C Uninsured/Underinsured Motorists

Part C - Uninsured Motorists (UM) and Underinsured Motorists (UIM)

Part C is first-party coverage that steps into the shoes of an at-fault driver who either has no insurance (Uninsured Motorist) or not enough insurance (Underinsured Motorist) to pay the insured's damages. Unlike MedPay, UM/UIM responds only when the other party is legally liable - the insured must be able to establish fault and damages against the phantom or under-insured driver.

UM coverage primarily pays bodily injury to the insured. Some states add Uninsured Motorists Property Damage (UMPD), but the bodily-injury form is the national-exam focus. UM/UIM limits are usually written as split limits or a CSL mirroring the liability limits.

Three Categories of Uninsured Vehicle

An "uninsured motor vehicle" includes:

1. A vehicle with no liability insurance at all;
2. A vehicle whose liability limits are less than the state minimum required;
3. A hit-and-run vehicle whose driver/owner cannot be identified (the "phantom" vehicle); and
4. An insurer that is insolvent or denies coverage.

Note what is excluded from the UM definition: your covered auto, a vehicle owned/operated by a self-insurer, a government-owned vehicle, and a vehicle the insured owns but did not list on the policy (the owned-but-not-insured / "family-owned" exclusion - you cannot collect UM on a relative's uninsured car you could have scheduled).

Underinsured Motorist Math

UIM applies when the at-fault driver has some liability insurance but less than the insured's damages. Two formulas exist by state; the exam usually tests the difference (excess) approach: UIM pays the gap between the insured's UIM limit and the amount actually collected from the at-fault driver.

Worked example: An insured carries $100,000 UIM per person. She suffers $90,000 in bodily injury caused by a driver carrying only the state-minimum $25,000 liability limit. Under the excess approach:

• At-fault driver's liability pays: $25,000
• Insured's UIM limit: $100,000
• UIM pays the difference: $100,000 - $25,000 = $75,000
• Total recovery to the insured: $25,000 + $75,000 = $100,000 (her full UIM limit)

Her remaining uncompensated loss is $90,000 - $100,000 = none here; if damages had been $130,000 she would absorb the $30,000 above her UIM limit.

Stacking, Offsets, and Tested Traps

Stacking lets an insured combine UM limits across multiple vehicles on one policy (or multiple policies) where state law permits - e.g., three cars each with $50,000 UM could yield $150,000 if intra-policy stacking is allowed. Many states and policies prohibit or limit stacking via an anti-stacking clause.

Other frequently tested points:

• UM/UIM is a mandatory offer in most states; the insured can often reject it only in writing.
• UIM limits generally cannot exceed the insured's own Part A liability limits.
• The at-fault driver's payment is offset (credited) against the UIM limit under the difference approach, not added on top.
• Punitive damages are typically not recoverable under UM/UIM.

Trigger Tests: UM vs. UIM

A reliable way to answer Part C questions is to apply two trigger tests in order. First, ask: does the at-fault vehicle have liability insurance at all? If no (or hit-and-run, or insurer insolvent, or below state minimum), the UM trigger fires. If yes but the limits are simply too small to cover the damages, the UIM trigger fires instead.

Second, for UIM compare the at-fault driver's limit against the insured's loss. UIM is meaningful only when the insured's own UIM limit exceeds the at-fault driver's liability limit; if the insured carries the same minimum limits as the negligent driver, the offset wipes out the UIM benefit. This is why agents recommend buying UM/UIM limits well above the state floor - a point the exam reinforces through scenario questions.

Arbitration, Limits, and the No-Stacking Trap

If the insurer and the insured disagree about whether the insured is legally entitled to recover or about the amount of damages under Part C, the policy provides for arbitration - each party selects an arbitrator and the two select a third, with local court rules of evidence applying. This dispute-resolution mechanism is unique to Part C and is occasionally tested.

Finally, beware the inter-policy anti-stacking trap: when an insured is covered under more than one PAP, Part C limits do not automatically add together. The policy on the occupied vehicle is usually primary, and any other applicable UM coverage is excess, with the maximum recoverable generally capped at the highest single applicable limit rather than the sum - unless the controlling state law expressly permits stacking. Read scenario facts carefully to identify which policy is primary and whether stacking is allowed.

UM vs. UIM and Stacking

PAP Part C protects the insured when the at-fault driver has no insurance or too little:

UM/UIM pays the BI (and in some states PD) the insured is legally entitled to recover from the at-fault uninsured/underinsured driver. Some states permit stacking — combining the UM limits of multiple vehicles or policies — while others prohibit it by anti-stacking language. Trap: the at-fault driver must be legally liable for UM to pay; a one-car accident caused by the insured does not trigger UM.

Worked UIM Example and the Phantom-Vehicle Rule

Worked example: the insured carries $100,000 UIM. An at-fault driver with only $25,000 liability limits causes the insured $80,000 in injuries. Liability pays $25,000; UIM then makes up the gap to the insured's damages — paying $55,000 ($80,000 − $25,000) under the difference-in-limits approach used in many states. The insured is made whole up to the UIM limit.

UM also reaches hit-and-run and phantom-vehicle claims, but states usually require corroboration (physical contact or independent witness) to deter fraud. Worked example: a hit-and-run driver flees after striking the insured; UM responds as if the unidentified driver were uninsured, subject to the state's physical-contact/witness rule. Trap: UIM in many states pays the difference between the insured's UIM limit and the at-fault limit, not the full UIM limit on top.