Homeowners and personal auto policies on the exam follow ISO standard forms closely. Umbrellas are different: there is no single form everyone uses.

ISO publishes a personal umbrella form, but using it is optional. Most carriers have developed their own umbrella forms. That is why coverage, exclusions, retentions and required underlying limits differ from company to company. Neither the Insurance Code sections on umbrella policies nor the ISO program creates one required form.

Practical result: two umbrellas with the same $1,000,000 limit can respond differently to the same claim. An agent should compare the actual forms, not just the premium. A lower price does not prove narrower coverage, and a higher price does not prove broader coverage.

Umbrella and excess liability policies are sold in both personal and commercial lines. The commercial side, where carriers' own forms are also the norm, is covered in the commercial casualty chapter.