The enforceability of anti-stacking clauses in Idaho took a hit
in the case of Gearhart v. Mut. of Enumclaw Ins. Co.,
2016 WL 4041704 (Idaho July 27, 2016). The dissenting opinion
calls the case facts "heartbreaking," which may help
explain why the majority's analysis took the route it did.
Trent Gearhart suffered a severe brain injury with permanent
cognitive defects in an automobile accident caused by an
underinsured motorist. Trent's divorced parents each had Mutual
of Enumclaw insurance policies naming Trent as a beneficiary and
providing $300,000 limits for accidents caused by underinsured
motorists. Each policy contained identical "other
insurance" provisions with anti-stacking clauses that read:
"If this policy and any other policy providing similar
insurance apply to the accident, the maximum limit
of liability under all the policies shall be the highest applicable
limit of liability under any one policy."
