6.4 Part C Uninsured/Underinsured Motorists

6.4 Part C Uninsured/Underinsured Motorists

Part C - Uninsured Motorists (UM) Coverage, with its companion Underinsured Motorists (UIM) coverage, protects the insured when an at-fault driver has no insurance or not enough insurance to pay the insured's bodily injury (and, in some states, property damage). It is first-party coverage that pays what the negligent uninsured driver would have owed. According to the Insurance Research Council (IRC, 2023), roughly 14% of U.S. motorists drive uninsured nationally, which is why most states require UM to be offered or carried.

Uninsured vs. Underinsured

The distinction is heavily tested:

A hit-and-run ("phantom vehicle") is treated as uninsured, though many states require physical contact or independent corroboration to prevent fraud. UIM steps in only when the other driver carries some coverage that proves inadequate.

UIM: Difference vs. Excess (The Offset Trap)

States apply one of two UIM approaches, and the math differs:

• Difference (offset) states: UIM pays the insured's UIM limit minus the at-fault driver's liability limit.
• Excess (add-on) states: UIM pays on top of the at-fault driver's payment, up to the UIM limit.

Worked example — insured carries $100,000 UIM; at-fault driver carries $25,000 liability; the insured's damages are $90,000:

• Difference state: UIM limit $100,000 − $25,000 = $75,000 available; insured collects $25,000 (other driver) + $65,000 (UIM) = $90,000.
• Excess state: UIM pays up to $100,000 over the $25,000; insured collects $25,000 + $65,000 = $90,000 here too, but if damages were $130,000 the excess approach pays the full $100,000 UIM ($125,000 total) versus only $75,000 in a difference state. Read the state rule carefully.

Limits, Stacking, and Consent-to-Settle

Key rules under Part C:

• UM/UIM limits are usually offered equal to the Part A liability limit unless the insured rejects higher limits in writing.
• Stacking (combining UM limits across multiple insured vehicles) is permitted in some states and barred by anti-stacking clauses in others.
• A consent-to-settle condition requires the insured to obtain the UIM insurer's permission before settling with the at-fault driver, protecting the insurer's subrogation rights. Settling without consent can forfeit UIM.
• Disputes over the amount the insured is "legally entitled to recover" are often resolved by arbitration under the policy.

UMPD and Common Exclusions

Some states add Uninsured Motorists Property Damage (UMPD) for damage to the insured's vehicle by an uninsured driver, sometimes with a deductible. Part C generally does NOT apply when:

• The insured settles without insurer consent, prejudicing subrogation.
• Bodily injury occurs while using a vehicle as a public or livery conveyance.
• The insured is injured in a vehicle owned by, but not insured under, the policy (the owned-but-not-insured / "family vehicle" exclusion), preventing an insured from collecting UM on an uninsured car they own.
• The claim duplicates amounts payable under Part A or workers compensation.

The Definition of an 'Uninsured Motor Vehicle'

The PAP's UM definition deliberately excludes certain vehicles so they cannot trigger UM:

• A vehicle insured under the same PAP's Part A (you cannot UM-claim against your own at-fault covered auto).
• A vehicle owned or operated by a self-insurer under any motor-vehicle law, unless that self-insurer is insolvent.
• A vehicle owned by a government unit or agency.
• A vehicle operated on rails or crawler treads, or designed mainly for use off public roads while not on public roads, or used as a residence/premises.

For a phantom-vehicle UM claim, most state endorsements require either physical contact or independent corroboration by a disinterested witness — a key fraud-prevention point. UIM, by contrast, is established by comparing the at-fault driver's exhausted liability limit to the insured's UIM limit, so identity and the other driver's actual limit must be proven.

Worked UIM 'Trigger' Numeric

UIM is triggered only when the at-fault driver's available limit is less than the insured's UIM limit (in difference states) or less than the insured's damages (the basic underinsured test). Example: insured carries 50/100 UIM; the at-fault driver carries 25/50 liability; the insured's proven damages are $60,000.

The other driver's BI limit ($25,000 per person) is below both the $50,000 UIM limit and the $60,000 damages, so UIM is triggered. In a difference state the UIM pays $50,000 − $25,000 = $25,000, giving the insured $25,000 + $25,000 = $50,000 — still $10,000 short, illustrating why buying UIM equal to or above your liability limit matters.

Part C - Uninsured and Underinsured Motorists

Part C (UM/UIM) pays the insured for bodily injury (and, where offered, property damage) caused by an at-fault uninsured or underinsured driver - essentially standing in for the missing or inadequate liability coverage of the other party. Uninsured Motorist (UM) applies when the at-fault driver has no liability insurance or is a hit-and-run ("phantom" vehicle). Underinsured Motorist (UIM) applies when the at-fault driver's limits are lower than the insured's damages.

Stacking and Offset

Some states permit stacking - adding UM/UIM limits across multiple vehicles or policies. UIM typically pays the difference between the insured's UIM limit and the at-fault driver's liability limit (or the actual damages, whichever is less), so the at-fault carrier's payment is offset against UIM.

Worked UIM Example

An insured carries $100,000 UIM and suffers $90,000 of bodily injury caused by a driver with only $25,000 of liability coverage. The at-fault carrier pays its $25,000. UIM then pays the gap: $90,000 damages - $25,000 already received = $65,000 (within the $100,000 UIM limit). The insured is made whole at $90,000. Had the insured carried only $50,000 UIM, the UIM payment would be capped at $50,000 - $25,000 = $25,000, leaving a shortfall - illustrating why matching UIM limits to liability limits matters.

UM/UIM is mandatory or must-be-offered in most states (insureds may reject UIM in writing where rejection is allowed). It does not cover the insured's own at-fault liability - it is first-party protection against other drivers' inadequate coverage.