Uninsured / Underinsured Motorist Claim Payout Calculator

When the at-fault driver carries no insurance or low policy limits, your own uninsured/underinsured motorist (UM/UIM) coverage fills the gap. Per the Insurance Research Council, 1 in 8 US drivers is completely uninsured and many more carry only state minimum coverage of $25,000 — far below the cost of even a moderate injury claim. UM/UIM payout equals your total damages minus what you collect from the at-fault driver, capped at your UM policy limit.

Two State Setoff Rules

Excess rule (majority): UM coverage stacks on top of the at-fault driver's payment. If you have $250K UM and the at-fault driver pays $25K, you can claim up to another $250K from UM = $275K total. Difference-in-limits rule: UM limit minus the at-fault limit. Same example: $250K − $25K = $225K available from UM = $250K total. Florida, Georgia, Texas, and several others use excess; New York, Pennsylvania, and a handful use difference-in-limits. Always check your state and policy language.

Why Stacking And Umbrella Coverage Matter

Many states allow inter-policy stacking — UM coverage on multiple vehicles in your household can be combined. Two cars with $100K UM each can yield $200K. Some states allow intra-policy stacking even on a single car. A $1M personal umbrella policy adds another layer of UM coverage at very low premium ($150-$400/yr). Most attorneys recommend UM coverage matching your liability limits — buying $500K liability with $25K UM is upside-down because you're better insured to hurt others than to protect yourself.

Last updated May 2026. Sources: Insurance Research Council — IRC.