Does Ohio Allow UM/UIM Stacking? What R.C. 3937.18 Says

By the FigureMyTax Editorial Team · How we calculate

Ohio makes UM and UIM coverage optional and lets a policy bar all stacking, without regard to premiums. Whether your limits add up depends on your policy language.

Optional coverage

Section 3937.18(A) says an auto liability policy may, but is not required to, include UM, UIM or both.

The stacking rule

Subsection (F) says a policy that includes UM or UIM may, without regard to any premiums, include terms that preclude any and all stacking, including interfamily and intrafamily stacking. Subsection (G) lets it treat all claims from one person's injury as a single claim subject to the per-person limit.

How UIM works

Under subsection (C), UIM applies when the limits available under all bodily injury liability policies covering the people liable are less than your UIM limits. It is not excess coverage, it provides no more than your UM coverage would if the other driver were uninsured, and your UIM limit is reduced by the amounts available under the liability coverage.

Other policy terms

A policy may require that a UM or UIM claim be brought within three years of the accident, so long as you have not prejudiced the insurer's subrogation rights (subsection (H)), and may exclude coverage in listed circumstances (subsection (I)). Workers' compensation benefits do not reduce UM or UIM (subsection (E)).

How to use this

Compare the results in the Ohio UM/UIM stacking calculator, start with the plain-English stacked versus single-limit explainer, and read how Ohio UM and UIM work.

This is general information, not legal advice, and the state comparisons above are illustrative, not an exhaustive survey. Confirm how Ohio's rules apply to your specific case with a licensed Ohio attorney.