Short answer: Stacking means adding the uninsured or underinsured motorist limits from several cars or policies together after a crash. Minnesota bans it. North Carolina lets you combine the highest UIM limit from each separate policy but not across vehicles on one policy. South Carolina ties extra coverage to the vehicle involved in the accident. Pennsylvania stacks by default unless you sign a waiver, while Ohio lets policies bar stacking, Iowa enforces antistacking language, and Nebraska caps recovery at the highest single policy limit.
Stacking rules can make a big difference after a serious crash with an uninsured or underinsured driver. Your policy wording matters too.
The table
| State | Stacking rule | Details | Source |
|---|---|---|---|
| Iowa | Antistacking provisions in auto policies are enforceable; the legislature abrogated a court decision that had allowed interpolicy stacking against policy language | The insurance commissioner must make sure policies or endorsements that provide stacking of UM and UIM coverage are available in the state | Iowa Code §516A.2 |
| Louisiana | No stacking: UM limits aren't increased because the policy covers several vehicles, or because you have UM under more than one policy | Riding in a car you, your spouse or a resident relative don't own: that car's UM is primary, and if it runs out you can recover excess from just one other UM coverage | La. R.S. 22:1295(1)(c) |
| Minnesota | No stacking: UM and UIM limits for two or more vehicles can't be added together for one accident, regardless of the number of policies, vehicles or premiums | Coverage generally follows the limit for one vehicle under a policy where the injured person is insured | Minn. Stat. §65B.49 subd. 3a |
| Nebraska | If you're entitled to UM or UIM coverage under more than one policy, the most you can recover is the highest limit of any one policy | When occupying a vehicle you don't own, that vehicle's coverage pays first and your other coverage is excess | Neb. Rev. Stat. §44-6411 |
| North Carolina | UIM across separate policies: you can combine the highest UIM limit available under each policy you're insured under | Within one policy, limits for different vehicles can't be combined (no intrapolicy stacking). Applies to nonfleet private passenger vehicles | N.C.G.S. §20-279.21(b)(4) |
| Ohio | Policies may include terms that preclude any and all stacking of UM and UIM coverage, regardless of premiums | This includes interfamily stacking (people not in the same household) and intrafamily stacking (family members in the same household) | Ohio Rev. Code §3937.18(F) |
| Pennsylvania | Stacking is the default: the UM/UIM limit applies separately to each insured vehicle, and the available limit is the sum for each vehicle on which you're an insured | A named insured can waive stacking by signing the statutory rejection form, and the premium must be reduced to reflect the waiver | 75 Pa.C.S. §1738 |
| South Carolina | Excess UM/UIM follows the vehicle involved: you're covered only to the extent of the coverage on that vehicle | If none of your vehicles is involved, coverage is limited to the coverage on any one vehicle with the excess or UIM coverage | S.C. Code §38-77-160 |
| Texas | UM/UIM policy forms must cap the total for any one person at the policy's stated limit regardless of the number of persons insured, policies, vehicles involved or claims made | The per-occurrence limit caps the total for all claimants | Tex. Ins. Code §1952.104(1) |
| Utah | No stacking: UM limits for two or more vehicles can't be added together for one accident | Exception: a named insured or insured family member hurt in a vehicle they don't own gets the highest UM limit on any one of their own vehicles, on top of the occupied vehicle's coverage (which is primary) | Utah Code §31A-22-305(7) |
We list only states where we read the official text ourselves in October 2026. A state that is missing is not covered here; check that state's statute or insurance department.
Questions to ask your agent
- How much UM/UIM do I have per person and per accident?
- Does my state or policy allow stacking, and is it worth higher limits instead?
- Who in my household is covered if they're hurt as a pedestrian or in someone else's car?
See uninsured motorist requirements by state and UMPD rules by state.
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Methodology
Each row was read from the official source linked in the Source column in October 2026. This is general information, not legal advice. See also the state insurance rules hub.
Frequently asked questions
What is UM/UIM stacking?
Adding together the uninsured or underinsured motorist limits from multiple vehicles or policies to increase the coverage available for one accident.
Does Minnesota allow stacking?
No. Minn. Stat. §65B.49 bars adding limits for two or more vehicles for any one accident.
Can I stack UIM in North Carolina?
Across separate policies, yes, by combining the highest limit under each policy. Not across vehicles on the same policy.
Alishahi Insurance · 439 N Canon Dr, Penthouse, Beverly Hills, CA 90210 · (877) 711-4545 · CA License #4348151. General information only. Not legal, tax or financial advice, and not a coverage determination. Coverage depends on policy language and underwriting, and rules vary by state.