Does Washington allow UIM stacking?

A Washington policy may limit it: the policy may provide that if you have other similar insurance, the total limits of all coverages cannot exceed the higher of the applicable limits, and may define its limit as the maximum for one accident regardless of the number of vehicles or premiums (RCW 48.22.030(5) and (6)). Check your policy for those clauses.

Is UIM required in Washington?

Insurers must provide it in the same amount as your liability coverage unless a named insured or spouse rejects it in writing (RCW 48.22.030(2) to (4)).

What is an underinsured vehicle in Washington?

One for which the sum of the liability limits applicable to you after the accident is less than the damages you are legally entitled to recover (RCW 48.22.030(1)). It compares limits to your damages.

What if I was partly at fault?

Your fault reduces your damages proportionally but does not bar recovery (RCW 4.22.005).

How long do I have to sue?

Three years for injury to the person (RCW 4.16.080(2)). For a person under 18 when the claim accrued, the time of the disability is not part of the period (RCW 4.16.190).

Washington UIM Stacking Calculator

Washington requires underinsured coverage equal to your liability limits unless rejected in writing, decides underinsurance by comparing limits to your damages, lets a policy cap total coverage at the higher of the applicable limits, and reduces but never bars recovery for your own fault. Enter your limits, damages and the other driver's coverage to see the results.

Cited to RCW 48.22.030 FigureMyTax Editorial Team Free · no sign-up

By the FigureMyTax Editorial Team · How we calculate

Estimate your UIM benefits

Enter your policy limits, your damages and the other driver's coverage.

UIM limit per person on the policy covering the vehicle you were in

UIM limit per person on another policy under which you are also insured (enter 0 if none)

Did a named insured or spouse reject UIM coverage in writing?

Does your policy limit the total from other similar insurance to the higher limit?

Your total damages (medical bills, lost income, pain and suffering)

Who caused the accident?

Total liability limits applicable to the at-fault driver (underinsured claims only)

Amount the at-fault driver's liability insurer actually paid you (underinsured claims only)

How is the other driver's coverage applied to your UIM?

Your own percentage of fault, if any (0 if none; fault reduces damages but never bars recovery)

Estimated result

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See what you keep after liens →

Washington decides underinsurance by comparing limits to your damages, lets a policy cap total UIM at the higher limit, and never bars recovery for your own fault

Washington's rules are in RCW 48.22.030. Fault is in RCW 4.22.005 and the deadline in 4.16.080.

Read how stacked and single-limit coverage differ in Washington, check what RCW 48.22.030 says, or see how Washington UIM works.

Injured in Washington?

A local personal injury attorney can review your claim — many offer a free consultation.

Talk to a Washington attorney

This is an estimate for general guidance only and is not legal advice. Figures are based on the cited Washington statutes. Confirm how these rules apply to your specific case with a licensed Washington attorney.

Washington UIM Stacking Calculator

Estimate your UIM benefits

Washington decides underinsurance by comparing limits to your damages, lets a policy cap total UIM at the higher limit, and never bars recovery for your own fault

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