There are major differences between ‘umbrella’ and ‘excess liability’ that you should know about. Both umbrella and excess policies are valuable because they provide coverage beyond underlying limits. The key difference between umbrella coverage and excess liability is that an umbrella is an open-peril policy – which means if it’s not specifically excluded, it’s covered. In contrast, an excess liability policy only covers what’s included in the underlying policy. This is an important distinction and one that could have major consequences. Talk to your insurance agent for further.
This is tidbits from Tom