What Is Add-On vs. Reduced-By UM Coverage in Georgia?
Short answer: They are the two ways Georgia uninsured motorist (UM) coverage can work with the at-fault driver’s liability insurance. Add-on UM (also called “added-to” or excess coverage) pays on top of the other driver’s limits. Reduced-by UM is offset by the other driver’s limits, so you may collect little or nothing extra.
Definition
When the at-fault driver has some insurance but not enough, your UM coverage helps fill the gap. With add-on coverage, your full UM limit is available after the other driver’s insurance pays. With reduced-by coverage, your UM limit is reduced by the other driver’s available liability coverage.
How it works in Georgia
- Add-on is the default: for policies issued or renewed on or after January 1, 2009, UM coverage applies in addition to the at-fault driver’s available liability coverage (O.C.G.A. § 33-7-11(b)(1)(D)(ii)).
- Reduced-by must be chosen in writing: you have reduced-by coverage only if an insured rejected add-on coverage and selected reduced-by in writing.
- Cost: add-on coverage usually costs somewhat more, and the difference in protection can be large.
- More than one UM policy: if you can claim under more than one policy, such as your own and a household member’s, each policy’s type affects how they combine.
Example
The at-fault driver has $25,000 in liability coverage. You have $50,000 in UM coverage and $100,000 in losses.
- Add-on: $25,000 from the other driver’s insurer plus up to $50,000 from your UM, for up to $75,000.
- Reduced-by: your $50,000 UM limit is reduced by the $25,000 already paid, so UM pays up to $25,000, for up to $50,000 total.
If your UM limit were only $25,000, reduced-by coverage would pay nothing extra.
Why it matters for your claim
- With the same limits, add-on coverage can mean a much larger recovery.
- Many people do not know which type they have until after a crash.
- Checking your policy now costs nothing.
Read more: Uninsured motorist coverage in Georgia and What happens if you are hit by an uninsured driver in Georgia.
Related terms
- Uninsured / underinsured motorist (UM) coverage
- Policy limits settlement
- Medical payments (med pay) coverage
Frequently Asked Questions
How can I tell which type I have?
Check your declarations page and any UM selection form you signed. If no one chose reduced-by coverage in writing, a Georgia policy issued or renewed since 2009 generally carries add-on coverage.
Can I switch to add-on coverage?
Usually yes, through your agent or insurer. A change generally applies going forward, not to a crash that has already happened.
Is add-on coverage the same as stacking?
Not exactly. Stacking usually means combining more than one UM policy. Add-on describes how one UM policy relates to the at-fault driver’s limits, though people often use the terms loosely.
Browse the full Georgia personal injury glossary
Questions about how this applies to your accident? Call 888-BIG-GUNN or request a free case review. There is no fee unless we win.
This is general information about Georgia law, not legal advice for your situation.



