How the layers stack
Suppose your auto policy carries a bodily injury limit of $250,000 per person and you cause a crash that ends in a $900,000 judgment. The auto carrier pays $250,000 and the defense to that point. A $1 million umbrella pays the remaining $650,000 and the defense from there. Without the umbrella the balance is collected from savings, from home equity above the state's homestead protection and, in the states we serve, from wages for years. The same stacking applies over the home policy for an injury on your property and over a boat or rental policy that is listed on the umbrella's schedule.