Ask five people why East Cobb's property taxes work differently than Alpharetta's or Milton's, and at least four will mention a state law that caps how fast your assessed value can climb. Fulton County opted into that protection, they'll say. Cobb County opted out. Buy on the Fulton side of the line and your tax bill grows slowly. Buy in East Cobb and it grows with the market.
It's a tidy story, and it's the reason relocating buyers keep asking Georgia agents to explain House Bill 581 before they'll write an offer on either side of the county line. The trouble is that the story leaves out the part of the tax bill that actually moves the needle, and it treats a temporary policy quirk as if it were a permanent feature of the market. Neither is true, and the gap between the headline and the mechanics is worth understanding before you decide which side of Johnson Ferry Road to buy on.
What The Cap Actually Covers
House Bill 581, Georgia's floating homestead exemption, took effect for the 2025 tax year. For a homesteaded property in a jurisdiction that participates, the taxable portion of your assessed value can only grow at the rate of inflation each year, even if your home's market value rises faster. Local governments got a one-time window to opt out by March 1, 2025.
Fulton County's government chose to opt in. County Commission Chairman Robb Pitts framed it as a commitment to property tax relief for homeowners when the decision was announced in early 2025, a position Appen Media covered in detail as North Fulton cities weighed their own responses. Cobb County's government went the other direction and opted out, meaning county-level assessments there continue to track full market value.
That's the part everyone repeats. It's also only a fraction of the story.
The Piece Everyone Skips
A Georgia property tax bill isn't one number. It's a stack: county government, county school district, and city government where one applies, each setting its own millage rate and each deciding separately whether to honor the inflation cap. School millage is almost always the largest single piece of that stack, frequently more than half the total bill.
Here's what the county-by-county opt-in coverage misses. Fulton County Schools opted out of the cap, even though Fulton County's general government opted in. Cobb County Schools opted out too, alongside Cobb's county government. So in both East Cobb and North Fulton, the largest line item on your bill still floats with the market in 2025 and 2026. The protection that made headlines applies only to the county government slice, which is a minority share of what you'll actually pay.
The cap that made headlines protects a fraction of your bill. The larger share, the school portion, still floats with the market in East Cobb and in Alpharetta alike.
That doesn't make the cap meaningless. It makes it smaller than the framing suggests, and it means the choice between East Cobb and North Fulton on tax grounds needs a different number to lean on.
What Happens The Day You Actually Buy
There's a second wrinkle that matters more to someone relocating right now than the cap does. Georgia's floating exemption resets whenever a home changes hands. A new owner starts a new base year at the property's current fair market value, according to the explainer Georgia Title and Escrow Company publishes for closing attorneys statewide. The exemption follows the homestead, not the parcel.
In practice, that means your first year of ownership looks the same in East Cobb and in Alpharetta regardless of which county opted into what. Your assessed value is set at whatever the home is worth at purchase, full stop. The inflation cap only starts protecting you in year two, and even then it only protects the smaller, county-government portion of your bill. If you're comparing two similarly priced homes across the county line this fall, the opt-in status of either government has no bearing on your first tax bill at all.
The Millage Stack Is The Number That Actually Persists
If the cap isn't the deciding factor, what is? The combined millage rate each jurisdiction sets, because that number applies from day one and doesn't depend on any opt-out policy that could change again before 2027.
Here's how the two sides of the comparison actually stack up using each government's own published 2026 figures.
| Component | Unincorporated East Cobb | Alpharetta |
|---|---|---|
| County general fund | 8.46 mills | 8.87 mills |
| City government | no separate city millage | 5.75 mills |
| Fire fund | 2.97 mills | included in county rate |
| School district | roughly 18.70 mills | roughly 18.50 mills |
| Approximate total | ~30.13 mills | ~33.12 mills |
Cobb County's Board of Commissioners confirmed its 2026 general fund rate would hold at 8.46 mills, with the fire fund at 2.97, in a press release announcing the county's proposed millage. The City of Alpharetta's own 2026 property tax guide sets its city millage at 5.750 mills, unchanged from the prior year, while Fulton County's general fund has held at 8.87 mills for five consecutive years.
Run those numbers against a $700,000 home, assessed at 40 percent of market value under Georgia law, and the gap between roughly 30 mills and roughly 33 mills works out to about $800 a year in raw millage before any exemptions apply. That's a real, durable difference. It has nothing to do with HB 581, the opt-out fight, or which government made which political statement in early 2025. It comes down to what each city and county actually charges to run itself.
An Expiration Date Already On The Calendar
Even the narrower cap advantage Fulton's county government holds over Cobb's has a shelf life. Georgia's General Assembly passed the HOME Act, Senate Bill 33, which Governor Brian Kemp signed on May 11, 2026. Starting with the 2027 tax year, the inflation cap becomes mandatory statewide. No county, city, or school district will be able to opt out anymore.
That means the entire debate over who opted in and who opted out resolves itself in about four months, since Georgia bases tax-year status on ownership as of January 1. Every homesteaded property in Georgia gets the same growth cap starting with the 2027 tax year, regardless of how any buyer chooses between East Cobb and North Fulton today. The one differentiator locals keep arguing about is set to disappear on its own.
What This Actually Means If You're Weighing East Cobb Against Alpharetta
If you're deciding between a listing in East Cobb and one in Alpharetta, Milton, Roswell, or Johns Creek this fall, the HB 581 opt-in question shouldn't carry much weight in that decision. It affects a minority slice of your bill, it treats you identically to your neighbor in year one no matter which side of the county line you land on, and it's set to become a non-issue statewide within two tax cycles.
What's worth asking instead is straightforward. Request the current combined millage for the specific parcel, not just the county average, since school district lines and special service districts can shift the number even within the same city. Confirm the homestead exemption deadline of April 1 if you plan to file for the year following your purchase. And keep the 45-day appeal window in mind once your first Notice of Assessment arrives, since a successful appeal locks your reduced value in place for three years under Georgia's assessment freeze rule.
The property tax question worth answering isn't who protected homeowners from inflation. It's what the county, school district, and city are actually charging this year, because that's the number that shows up on your bill no matter what the legislature decides to do next.
A Few Questions Worth Asking Directly
Does the HB 581 cap apply to a home I just bought, or only to homes I've owned for years? Only after your first year. Georgia resets your assessed value to full market value the moment ownership changes, so the cap has nothing to protect in year one regardless of jurisdiction.
If Cobb County opted out, does that mean my school taxes will rise faster in East Cobb than in Alpharetta? Not necessarily. Both Cobb County Schools and Fulton County Schools opted out of the cap, so the largest portion of the bill floats with the market in both places under current rules.
Will this comparison still matter in a couple of years? Only the raw millage will. The opt-in and opt-out distinction disappears statewide starting with the 2027 tax year once Georgia's HOME Act takes full effect.
If you're weighing a move between East Cobb and the North Fulton suburbs, the number that actually determines your bill deserves more attention than the one making headlines. Occasio Collective walks relocating buyers through the real millage math, parcel by parcel, before an offer ever gets written. Receive Exclusive Listings to see how the comparison looks for the neighborhoods you're actually considering.
