Stacked vs. Unstacked Insurance

When you’re out on the road, car insurance can offer you greater protection – especially when it involves uninsured or underinsured drivers.

Stacked auto insurance is a way to increase your uninsured motorist and underinsured motorist coverage by combining the bodily injury limits of each vehicle on your policy. This coverage can be more expensive than unstacked insurance and it isn’t available in every state.

Let’s take a look at the pros and cons of stacked and unstacked auto insurance to help you make an informed decision about whether this type of coverage is right for you.

What’s the Difference between Stacked and Unstacked Insurance?

Stacked insurance allows you to combine uninsured motorist coverage (UM) limits from multiple policies or from multiple cars on the same policy, essentially "stacking" the limits to increase their overall protection.

In the case of bodily injury liability, uninsured motorist coverage provides protection if you’re involved in an accident with an uninsured or underinsured driver. Without stacking, you would only have access to the coverage limit of the specific vehicle you were driving at the time of the accident.

Bear in mind that while the payout is generally higher with stacked insurance, it also costs more than unstacked insurance.

Unstacked Insurance

Unstacked insurance applies uninsured motorist bodily injury coverage limits to one specific vehicle, instead of combining coverage amounts for any additional vehicles covered under the policy. 

This type of insurance is typically less expensive than stacked coverage. However, it may provide less protection. For example, if you were involved in a serious accident with an uninsured or underinsured driver, you would only have access to the coverage limit of the vehicle you were driving, which might not be enough to pay all costs associated with the accident.

Stacked Insurance

When you stack your coverage, you can increase your protection by combining the coverage limits of all vehicles on the policy, providing added financial security in the event of an accident with an uninsured driver. This means that, in the event of a serious accident, you would have access to a higher overall coverage limit. This can help to lessen the financial impact of medical bills and other expenses related to the accident.

Only uninsured motorist or underinsured motorist bodily injury coverage can be stacked. You can’t stack uninsured motorist and underinsured motorist property damage coverage.

How Insurance Stacking Works

There are two ways to stack auto insurance: horizontally and vertically.

Horizontal stacking refers to having coverage under multiple policies for the same vehicle. 

Vertical stacking refers to having one policy for different vehicles that are all owned by the same individual. 

Both methods of stacking allow you to increase your coverage limits and potentially receive a greater payout in the event of an accident.

Vertically Stacked Insurance

Vertically stacked insurance refers to having one policy for different vehicles that are all owned by the same individual. The vehicles are “stacked” one on top of the other on a single policy, hence the term "vertical stacking." With this method of stacking, you can increase your coverage limits and receive a greater payout in the event of an accident involving any of your vehicles. 

As an example, if you have a vertically stacked policy and you get into an accident with your car, your policy would pay out up to the coverage limit. If the damage exceeds the coverage limit on your personal car policy, you may be able to draw from the coverage of your policy on a second vehicle.

Horizontally Stacked Insurance

With horizontal stacking, policies are stacked side by side. This practice aggregates the coverage you have for different vehicles under different policies. An aggregate limit refers to the total claim costs your insurance provider will cover during a given policy term. 

For instance, if you own two vehicles and insure them under different policies, you can combine your uninsured motorist (UM) coverage. If you’re involved in a car accident, horizontal stacking allows you to combine the UM coverage of all of your vehicles on each of your policies to pay for the damage (or total loss) of one vehicle on just one claim. 

How to Get Stacked Insurance

Your ability to purchase stacked insurance depends on your insurance company, the state you live in, and your existing coverage.

Because not all insurance companies allow stacking, be sure to check with your current insurance provider to see if they offer stacked auto insurance options. Typically, you’re required to have more than one insured car on your policy to be eligible for a stacked car insurance policy.

In addition, stacked car insurance isn’t available in all states. In states that allow stacked insurance, insurers may have the ability to opt out of stacking.

An independent insurance agent can answer your questions and help guide you through the nuances of stacked insurance. They can review your needs and let you know if it makes sense to include stacked insurance in your policy.

States That Allow Insurance Stacking

Not all states allow insurance stacking. Of the states that do, some only allow vertical stacking while others only allow horizontal stacking. To date, 32 states allow at least one type of insurance stacking, while 18 states prohibit it.

If your state supports stacked policies, it’s a good idea to check with your insurance agent to see if there are limits as to how many vehicles you can stack on a policy. Similarly, if you live in a state such as Pennsylvania or Florida that automatically defaults to stacking, you may want to flag to your insurer that you’d like to opt out so you can have a lower premium.

Types of Insurance Stacking Each State Allows

State	Intrapolicy (Vertical) Stacking	Interpolicy (Horizontal) Stacking
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Florida
Georgia
Hawaii
Idaho
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming

Choosing Stacked vs. Unstacked Auto Insurance

Is it better to have stacked or unstacked insurance? Because of the high number of uninsured drivers on the road, you might want the extra protection of stacked insurance. If you get into an accident caused by an uninsured driver, it can be hard to get compensation for bodily injury.

Consider getting stacked insurance if:

• Your state allows stacking
• Your insurance company allows stacking
• You have multiple vehicles
• Your local area has a high percentage of uninsured drivers

Choosing the right coverage for your needs can be complicated. That’s why it’s best to work with an independent insurance agent. They’re experts in the industry and can help simplify the process.

Stacked Insurance Advantages & Disadvantages

Let’s look at the pros and cons of stacked insurance.

Pros:	Cons:
You can get higher limits of uninsured motorist coverage.	To stack limits, you need to have more than one vehicle insured.
Stacking is helpful in states with a higher percentage of uninsured drivers.	Stacking is not allowed in all states.
You can often stack limits across multiple auto policies.	Many insurance companies don't allow stacking.
	Premiums are more expensive.
	Coverage doesn’t apply to uninsured motorist property damage.

Unstacked Insurance Advantages & Disadvantages

Now, let’s look at the pros and cons of unstacked insurance.

Pros:	Cons:
Your premiums are typically lower.	You’ll have a lower coverage limit than with stacked insurance.
You don’t have to worry about stacking regulations.	You can’t combine limits from another policy or vehicle in order to get more coverage following an accident.

FAQs about Stacked vs. Unstacked Car Insurance