Muehlenbein v. West Bend Mut. Ins. Co
In Muehlenbein v. West Bend Mut. Ins. Co., 175 Wis. 2d 259, 499 N.W.2d 233 (Ct. App. 1993), the Court addressed whether an exclusion "endorsement to an insurance policy expanded the scope of the policy, when the body of the policy was clear and unambiguous and did not mention the coverage excluded by the endorsement." Id. at 262.
The Court concluded that, "rather than creating an ambiguity, the endorsement at issue ... actually eliminated a potential ambiguity in the body of the umbrella policy." Id. at 265.
The exclusion endorsement merely clarified the insurance policy, but did not expand its scope. See id. at 262.
The policy in Muehlenbein made no other reference to underinsured motorist coverage.
The Court recognized a potential ambiguity in the umbrella policy when the underlying policies were considered in conjunction with the "Other Insurance" provision of the umbrella policy. See id. at 268. The exclusion endorsement, however, clearly and unambiguously excluded underinsured motorist coverage, and eliminated the potential ambiguity in the body of the umbrella policy. See id. at 269.