Basics
Umbrella insurance in plain language
An umbrella policy adds liability limits above the auto and homeowners policies. It is not a second copy of those policies.
Auto and homeowners policies include liability limits. When a claim is larger than those limits, the rest can fall to the person who was sued. An umbrella, or personal excess liability policy, sits above the required underlying limits and pays covered liability claims that exceed them. A common umbrella starts at one million dollars. The premium is often modest next to that limit because large claims are uncommon, not because the coverage is decorative.
It has a floor under it
Insurers require the auto and home policies to carry at least a stated liability limit before they will issue the umbrella. If you drop the auto limit later, the umbrella can refuse to respond in the gap. The umbrella also has its own exclusions. Business activity, some watercraft, and intentional harm are frequent ones. A side business usually needs a separate commercial policy, not a personal umbrella.
Who looks at it
People look at an umbrella when a lawsuit could reach wages, savings, or a house: a teen driver, a property that guests visit, a dog, or a public role. It does not pay to repair your own car or your own roof. Those remain collision and property claims on the underlying policies.
Underlying-limit requirements differ by insurer. Read the umbrella application next to the auto and homeowners declarations before you assume they stack.