Stacking insurance is an option in some states that lets you make claims for injuries from one accident using two uninsured motorist insurance (UM) policies. If an uninsured (or underinsured) driver hits you and you have medical bills not covered by their insurance, stacking gives you the potential to get more money for injuries than you'd be able to get with just one UM policy.

To get stacked auto insurance, you must:

  • Live in a state that allows stacking (see chart below).
  • Have uninsured/underinsured motorist (UM/UIM) coverage on either 1) two vehicles under one policy or 2) two vehicles under two separate policies. Where you live will determine if and how you can stack policies.

Some states that allow stacking also let insurers choose not to offer stacking. If your policy has an "anti-stacking provision," you won't be able make multiple UM claims for one accident.

2 ways to stack UM insurance

If you can stack UM coverage, here's how it could work:

Example 1: Stacking insurance within one policy

  • Say you have coverage for two cars under one policy, both with $50,000 in uninsured motorist bodily injury coverage. If a driver without enough insurance hits one of the cars, you can claim up to $100,000 in medical benefits.

Example 2: Stacking insurance from two policies

  • Say you have coverage for two cars under two separate auto insurance policies, both with $50,000 in uninsured motorist bodily injury coverage. If a driver without enough insurance hits one of the vehicles, you can claim up to $100,000 in medical benefits. Both policies must be in your name.

Things to consider before stacking

  • You may have to pay more for the option to stack. If this is the case, you need to elect stacking when you buy the policy. You can't retroactively select it after an accident.
  • Health insurance plans typically also cover injuries from auto accidents. You may not even need UM insurance. (Although some states require UM.) But if your health plan has high out-of-pocket charges, buying UM is a way to cover car accident injuries without dealing with health insurance deductibles, coinsurance and copays.
  • UM/UIM coverage is for accidents caused by others. If you cause an accident and are injured, UM coverage won't help you. (But personal injury protection or medical payments coverage would.)

How to make a claim with stacked UM insurance

If a driver with no liability insurance hits you and causes injuries: You'd make a claim on your own UM coverage for medical bills. If that's not enough, you'd tap the UM coverage from another vehicle you own or from another auto insurance policy you have.

If a driver with some liability insurance hits you and causes injuries: You'd first make a claim against the other driver's liability policy for your injuries (and property damage). If their liability insurance isn't enough to cover your injuries, you'd turn to your own UM/UIM coverage. If the coverage for one vehicle (or under one policy) still isn't enough, you'd tap other UM coverage you have for another vehicle or from another policy.

State laws on stacked insurance

State Stacking with multiple policies? Stacking within one policy?
Alabama Yes. If there are separate policies, there is no stacking limitation. Yes, up to three vehicles.
Alaska No No
Arizona No No
Arkansas Yes, unless policy unambiguously disallows. Yes, unless policy unambiguously disallows.
California No No
Colorado Yes Yes; however, anti-stacking provisions are allowed. A single policy or endorsement for UM or UIM coverage issued for a single premium covering multiple vehicles may be limited to applying once per accident.
Connecticut No No
Delaware Yes No; however, when two or more vehicles are insured under one policy, the limits of liability apply separately to each vehicle, but the recovery must not exceed the highest limit of liability under any one vehicle.
District of Columbia No, so long as policy language is clear. No, so long as policy language is clear.
Florida Yes, unless waived in writing on state-approved form. Yes, unless waived in writing on state-approved form.
Georgia Yes No
Hawaii No Yes; insurer must offer insured option to purchase stacking; stacking of fleet vehicles not allowed.
Idaho No, if policy language clearly and unambiguously prohibits stacking. No, if policy language clearly and unambiguously prohibits stacking.
Illinois No. Anti-stacking clause is enforceable if unambiguous and not in violation of public policy. No, when anti-stacking provision is clear and unambiguous.
Indiana No, unless policy language is ambiguous. Yes, if separate and specific premium is charged for UM coverage and policy is ambiguous. If policy language is clear and unambiguous, the stacking of coverages under a single policy is not permitted.
Iowa No; however, if more than one policy or coverage applies to an accident, insured may choose to apply coverage with highest limits. No, if policy language is clear.
Kansas No No
Kentucky Yes, if a separate premium is charged for each vehicle. Yes, if a single premium is paid.
Louisiana No No
Maine No, unless anti-stacking language is ambiguous. No, unless anti-stacking language is ambiguous.
Maryland No No, if policy language is clear and unambiguous.
Massachusetts No No
Michigan No No
Minnesota No No
Mississippi Yes Yes
Missouri Yes Yes
Montana Yes Yes
Nebraska No No
Nevada Yes Yes
New Hampshire Yes, whenever policy terms are ambiguous. Yes, unless policy prohibits stacking through clear and unambiguous policy language.
New Jersey Yes No
New Mexico Yes, but injured people not in the policyholder's household may not stack. Yes; however, a policy containing anti-stacking language must be "truly unambiguous" and specify single premium for single coverage.
New York Yes No
North Carolina Yes No
North Dakota No No
Ohio Yes; unless clearly excluded by policy. Yes; unless clearly excluded by policy.
Oklahoma Yes, unless policy contained clause excluding multiple recoveries and only one premium for UM coverage was paid. No, if policy language is clear.
Oregon Yes; anti-stacking clauses are unenforceable. No
Pennsylvania Yes Yes, but only members of the policyholder's household can stack.
Rhode Island Yes, if insured pays separate premiums. Yes, if insured pays separate premiums.
South Carolina Yes, limited stacking is permitted. Yes, unless policy includes anti-stacking clause.
South Dakota No No
Tennessee No No
Texas Yes No
Utah Yes for UM; no for UIM No
Vermont Yes, where insured has paid separate premiums. Yes; unless policy clearly and unambiguously precludes stacking.
Virginia Yes; unless policy contains clear and unambiguous language prohibiting stacking. No; if anti-stacking language is clear.
Washington No, if anti-stacking language is clear. No
West Virginia Yes Yes, but anti-stacking provisions allowed.
Wisconsin Yes, but anti-stacking language is permitted. Yes, but anti-stacking language is permitted.
Wyoming Yes No; so long as anti-stacking language is clear.
Source: American Property Casualty Insurance Association