If you're shopping for auto insurance in Brentwood, CA, you’ve probably come across the terms stacked and unstacked car insurance. They might sound technical, but the difference between them could have a big impact on your coverage — and your wallet.
This post will break down what these two terms mean, how they apply in California (yes, there’s a twist), and how to make sure you’re saving money without sacrificing the protection you need.
Before we get into stacked vs. unstacked insurance, let’s talk about the coverage they apply to.
Uninsured/Underinsured Motorist (UM/UIM) coverage kicks in when:
It’s optional in California, but incredibly valuable — especially when you consider that millions of drivers in the state are either uninsured or underinsured.
Stacked insurance means you can combine (or "stack") your UM/UIM coverage limits across multiple vehicles on your policy. This increases your potential payout if you're in an accident caused by an uninsured or underinsured driver.
Say you have two cars, and each has $30,000 per person/$60,000 per accident in UM/UIM coverage. If you stack your policy, you can double your limit:
That’s a huge upgrade in protection — without doubling your premium.
Unstacked insurance means each vehicle’s coverage is treated separately. You can only use the limits of the vehicle involved in the accident.
Using the same example:
Unstacked coverage is more limited but usually comes with lower premiums.
Here’s where it gets interesting.
California does not allow stacking of uninsured/underinsured motorist coverage.
That means whether you insure one vehicle or five, your UM/UIM coverage cannot be combined. Your maximum payout is limited to the coverage listed on the specific vehicle involved in the accident.
So, why talk about it?
If you’re relocating from another state or managing multi-state policies, it’s still crucial to understand. Plus, many insurance companies use the stacked/unstacked framework in their marketing — even in states where stacking isn’t allowed.
Even though you can’t legally stack coverage in California, there are creative, smart ways to structure your policy to get similar benefits.
Here’s how:
Since you can’t combine coverage, make sure the coverage on each vehicle is high enough to protect you in a worst-case scenar
Remember, the new minimum auto insurance limits in California (as of Jan 1, 2025) are:
These are just the minimums — they may not be enough to cover serious injuries or multiple passengers.
Many people assume that coverage automatically extends to every driver in the home. It doesn’t.
To maximize protection, make sure all licensed drivers in your household are listed on your policy — and that each of their vehicles has robust UM/UIM coverage.
Even though stacking isn’t allowed, bundling multiple cars on the same policy can lead to lower rates and better coverage options.
A knowledgeable agent in Brentwood can help you balance high coverage limits with cost-saving opportunities.
A personal umbrella policy provides extra liability coverage that kicks in after your standard auto policy limits are exhausted. It’s a great backup plan and can often be added for a small monthly cost.
Technically, stacked coverage costs more, but gives you significantly better protection if it’s available.
In states like Pennsylvania or Florida, it can be a lifesaver. In California, though, since stacking isn’t permitted, the real “money-saving” decision comes down to:
If you live in Brentwood or the greater Contra Costa County area, you know California drivers face unique risks: wildfires, earthquake-prone regions, heavy traffic corridors, and uninsured motorists.
Here’s how to choose the right policy — stacked or not:
Unlike big-name national insurers, local insurance brokers in Brentwood, CA understand the market, laws, and risks you actually face. They can recommend UM/UIM limits that reflect real-life driving conditions, not just state minimums.
Insurance isn’t one-size-fits-all. At Circadian Insurance Brokers, we’ll review your current coverage and identify:
Saving money is important — but not if it leaves you exposed in an accident. Instead, aim for value: strong coverage at a reasonable rate.
When you work with a broker, we’ll shop rates from multiple carriers to find the perfect balance.
If you’re in a state where stacking is legal, stacked coverage is often worth the slightly higher premium for the added protection.
But in California, your focus should shift. Since stacking isn’t allowed, the smartest move is to:
If you’re not sure whether your current auto insurance meets the new California standards — or whether it protects you from uninsured drivers — now is the time to act.
At Circadian Insurance Brokers, we specialize in auto insurance in Brentwood CA, and we’re here to make insurance simple, smart, and affordable.
Request a free quote or policy review today. We’ll make sure you’re fully covered — and never overpaying.
Circadian Insurance Brokers — Your Local Auto Insurance Experts in Brentwood, CA
