How Does Uninsured Motorist Coverage and Stacking Work in Georgia?

Uninsured/underinsured motorist coverage is one of the most important protections a Georgia driver can have, but it is also one of the most misunderstood. Whether your coverage adds to or is reduced by the at-fault driver’s insurance can dramatically change how much you recover. This guide explains what UM/UIM coverage is, add-on versus reduced UM, stacking across policies, and how to know your coverage type.

What UM/UIM Coverage Is

Uninsured/underinsured motorist coverage, UM/UIM, is coverage on your own auto policy that protects you when the at-fault driver cannot fully pay for your injuries. It applies in three main situations: when the at-fault driver has no insurance at all (uninsured), when the at-fault driver has insurance but not enough to cover your damages (underinsured), and when the at-fault driver flees and cannot be identified (a hit-and-run, covered in the related post).

Under Georgia’s uninsured motorist statute, O.C.G.A. § 33-7-11, insurers are not allowed to issue an auto policy in Georgia without including UM/UIM coverage unless the policyholder rejects it in writing. In other words, UM/UIM is not mandatory for the driver to buy, but the insurer must offer it, and it is included by default unless you opt out in writing. When you carry it, your own insurer effectively stands in for the at-fault driver up to your UM/UIM limits.

Add-On vs. Reduced UM

The single most important feature of Georgia UM/UIM coverage is whether it is “add-on” or “reduced-by,” because this determines how your coverage interacts with the at-fault driver’s liability limits. Georgia recognizes both types under O.C.G.A. § 33-7-11(b)(1)(D)(ii).

With add-on coverage, also called excess or stacking coverage, your UM/UIM benefits are paid on top of the at-fault driver’s liability coverage. For example, if the at-fault driver has $25,000 in liability coverage and you have $100,000 in add-on UM, your total available coverage is up to $125,000, the at-fault driver’s $25,000 plus your full $100,000. With reduced-by coverage, also called traditional or offset coverage, your UM/UIM benefits are reduced by the amount available from the at-fault driver. With the same numbers, $25,000 from the at-fault driver and $100,000 in reduced-by UM, your UM pays at most the difference, $75,000, for $100,000 total. Under reduced-by coverage, if the at-fault driver’s limits equal or exceed your UM limits, your UM may pay nothing. Add-on coverage typically costs somewhat more but provides meaningfully greater protection.

Stacking Across Policies

“Stacking” refers to combining UM/UIM coverage to increase the total available. Add-on coverage is itself a form of stacking, because it layers your UM on top of the at-fault driver’s liability rather than offsetting it. Beyond that, in some situations a person may have access to UM coverage under more than one policy, for example, coverage on multiple vehicles or, in some cases, coverage available to a resident relative, which can increase the total protection available.

A pivotal change came in 2008, when Georgia amended the statute, effective in 2009. Before that change, drivers were largely limited to reduced-by coverage. The amendment made add-on (stacking) coverage the default, requiring insurers to provide it unless the insured rejects it in writing in favor of reduced-by coverage. This shift significantly strengthened the protection available to Georgia drivers, but the type a driver actually has still depends on what was selected, which is why understanding the distinction matters so much.

How to Know Your Coverage Type

Because the difference between add-on and reduced-by can be worth tens of thousands of dollars after a serious crash, knowing which type you have is important. The coverage type is reflected in your policy documents, and the declarations page is generally where you can confirm your UM/UIM limits and, often, the type of coverage. If it is unclear, your insurer or agent can tell you whether your UM is add-on or reduced-by.

Given the 2009 default in favor of add-on coverage, many policies issued or renewed since then will be add-on unless the insured affirmatively chose reduced-by in writing. But assumptions are risky: a driver who selected reduced-by, perhaps to save on premiums, may have far less protection than they expect. Reviewing the declarations page, confirming the coverage type and limits, and asking whether higher or add-on coverage is available are practical steps to understand the protection in place before it is ever needed. Whether coverage is add-on or reduced-by, and how much is carried, frequently determines whether a seriously injured person is made whole.

Key Takeaways

• UM/UIM coverage on your own policy protects you when the at-fault driver is uninsured, underinsured, or unidentified; insurers must offer it unless you reject it in writing (O.C.G.A. § 33-7-11).
• Add-on (excess) UM pays on top of the at-fault driver’s limits, while reduced-by (offset) UM is reduced by those limits, a difference that can be worth a great deal.
• Since a 2008 amendment effective in 2009, add-on (stacking) coverage is the default unless the insured chooses reduced-by in writing.
• Your declarations page and insurer can confirm whether your UM is add-on or reduced-by; do not assume, because the type significantly affects your recovery.

This article provides general information about Georgia law and is not legal advice. Statutes and court decisions change, and how the law applies depends on the specific facts of a situation. For advice about a particular matter, consult a licensed Georgia attorney.