In Jordan v. Safeco, the 8th Circuit reversed a lower court decision against stacking underinsured motorist coverage (UIM).  The 8th Circuit disagreed with the trial court regarding the application of  Ritchie v. Allied Property & Casualty Insurance Co., 307 S.W.3d 132 (Mo. 2009), which permitted the  stacking of underinsured motorist coverage, and reversed summary judgment to Safeco, remanding for entry of partial summary judgment in favor of the insured, Jordan.  The district court ruled the Ritchie decision permitted the stacking of UIM coverage only applies to situations where the insured is occupying a non-owned vehicle.  Thus, the Other Insurance clause in the Safeco policies was not applicable to Jordan because she was a pedestrian. And, absent the applicability of the Other Insurance clause, the policies unambiguously prohibit the “stacking” of UIM coverage.

In its discussion, the 8th Circuit notes that UM — Uninsured Motorist coverage may be stacked and non stacking policies have been struck down.  But there is no public policy which prohibits non stacking underinsured  (UIM) policies. In Ritchie, the Missouri Supreme Court held that the "other insurance clause" made the policy ambiguous, and that the holding was not limited to situations when the insured is occupying a non-owned vehicle.