6.4 Part C Uninsured/Underinsured Motorists

The Problem Part C Solves

Even with compulsory insurance laws, many at-fault drivers cannot pay. The Insurance Research Council (IRC) has reported roughly one in seven U.S. drivers is uninsured, and a much larger share are underinsured.

Part C - Uninsured/Underinsured Motorists Coverage is first-party protection that steps into the at-fault driver's shoes: it pays the insured the bodily injury damages the insured would have collected from a responsible driver who has no or too little coverage.

The controlling gate: the other driver must be legally liable. Part C never pays when the insured is at fault.

First-Party Coverage That Mimics Third-Party Recovery

The defining feature of Part C is that it is first-party coverage that pays the insured what a third-party liability policy would have paid if the at-fault driver had carried one. The insured's own insurer effectively becomes the substitute liability carrier for the negligent driver.

Because of that design, the insured must still prove the other driver's negligence and the amount of damages, exactly as in a liability claim. UM/UIM does not turn into a no-fault medical benefit like Part B; it pays the full range of bodily injury damages - medical bills, lost wages, and pain and suffering - up to the Part C limit, but only when the other driver is legally responsible.

Uninsured Motorist (UM)

UM pays the insured's bodily injury caused by:

• A driver carrying no liability insurance.
• A hit-and-run or phantom (unidentified) vehicle.
• A driver whose insurer is insolvent.

Worked example - $100,000 UM limit:

Hit-and-Run Requirements

Many states require physical contact between the phantom vehicle and the insured before UM applies; others permit a no-contact claim with independent witness corroboration. A prompt police report (often within 24 hours) is typically required.

Underinsured Motorist (UIM) - The Two Offset Methods

UIM applies when the at-fault driver has insurance but the limit is less than the insured's damages. Two calculation approaches are heavily tested and produce different results.

Assume $100,000 UIM, the at-fault driver carries $25,000 liability, and the insured's proven damages are $80,000.

The excess/damages method makes the insured whole (caps recovery at actual damages); the difference/limits method can let total recovery reach the UIM limit. The applicable method is set by state law.

State Mandates and the Rejection Requirement

Many states require insurers to offer UM and UIM at limits equal to the insured's Part A liability limits, and the insured may reject or reduce them only in a signed written waiver. If no valid rejection is on file, courts in some states will read the coverage in at the liability limit by default - a heavily tested consumer-protection rule.

The lesson for producers: document UM/UIM selections and rejections carefully, because an undocumented waiver can expose the insurer to limits it never intended to write.

Stacking, Offsets, and Common Exclusions

Stacking lets an insured combine UM/UIM limits across multiple covered vehicles or policies; some states permit it, others bar it by policy language or statute.

Tested exclusions and limits:

• The insured cannot recover under Part C and then also collect duplicate Part A from the same insurer for the same loss - payments are coordinated to avoid double recovery.
• UM/UIM generally excludes the named insured's own vehicles that are not covered autos (an "owned but not insured" vehicle).
• A vehicle owned or operated by a self-insurer or a government entity is often not an "uninsured motor vehicle" by definition.
• UM is primarily bodily injury; Uninsured Motorist Property Damage (UMPD) is a separate, state-optional coverage.

UM vs. UIM at a Glance

The single most reliable way to answer a Part C question is to first decide which coverage applies, then apply the offset.

UM and UIM are usually written with the same limit, and a single Part C limit caps the total payable for one accident regardless of how many insureds are hurt, subject to the per-person sub-limit when split limits are used.

Arbitration, Consent-to-Settle, and Recovery Timing

Part C contains procedural conditions that decide real claims. If the insured and insurer disagree on whether the insured is legally entitled to recover or on the amount of damages, the dispute is resolved by arbitration in many policy forms or state programs.

A crucial trap is the consent-to-settle rule: before accepting a settlement from the at-fault driver's insurer, the insured should obtain the UIM insurer's consent, or the UIM insurer may deny coverage for impairing its subrogation rights against the at-fault driver. After paying a UM/UIM claim, the insurer is subrogated to the insured's right to pursue the at-fault party.