Marietta's City Line Decides How Much of Your Tax Bill Stays Frozen

Pick two homes with a Marietta mailing address, one inside the City of Marietta limits and one in unincorporated Cobb County, and pull the sellers' property tax bills. They may look like a fair way to compare the two. For 2026, the headline rates are close. A home inside the city pays a combined 31.122 mills, and a home in unincorporated Cobb pays 30.13, according to the Cobb County Tax Commissioner's 2026 millage rate table.

The two rates are made up differently, though, and that changes what a seller's bill can tell you. On the city side, a larger share of the rate falls under homestead freezes that last as long as the current owner does. When the home sells, those freezes end, and the buyer's bill is figured from a new starting point. Inside the city, the seller's bill is a weaker guide to the buyer's future bill.

Two rates that look alike

Here is how the 2026 rates break down for a standard address on each side of the line. Properties in the Marietta Downtown Development Authority district or the Gateway Marietta CID carry extra levies on top of these figures.

In the city, the frozen layers add up to 13.152 of the 31.122 mills, a little over 42 percent of the rate. In unincorporated Cobb, only the 8.46-mill County General layer is frozen, which is about 28 percent of 30.13. The share of the rate that rises with market value runs the other way. It is 17.97 mills inside the city and 21.67 mills outside it.

Where the freezes come from

Two separate local laws cover the two frozen layers, and they work in similar ways.

• The City of Marietta's exemption. The city adopted its floating homestead exemption in 2002. In its 2026 millage announcement, the city says the exemption has "frozen property tax assessments of city taxes on residential properties that are owner-occupied at the original purchase value until it is sold." The same June 30, 2026 notice says the city kept its rate at 4.692 mills for the 25th year in a row.
• Cobb County's exemption. This covers the County General fund. In its 2026 budget and millage update, the county said homesteaded owners would "see no change in their County M&O tax bill" for 2026 if they had made no changes that affect the property's taxable value. The county kept the rate at 8.46 mills, so the frozen value and the unchanged rate together kept that line flat.

Commissioners adopted the 8.46 General and 2.97 Fire rates on July 28, 2026, Cobb County reported. The county's exemption goes back to a 2000 state act and took effect January 1, 2001. A later homestead claimant's base year is the year just before they became eligible, and it stays tied to that base until the home sells or the exemption is withdrawn.

Both layers have been in place for more than twenty years. A seller who bought in the early 2000s may still be paying city and county general taxes on a value set around that time.

The school line has no statewide cap

Georgia's HB 581 created a statewide floating homestead exemption that local governments could reject. The Georgia Secretary of State's HB 581 list shows opt-outs from all four bodies that tax a Marietta-area home: the Cobb County Board of Education, Marietta City Schools, the Cobb County Board of Commissioners, and the City of Marietta. When Cobb opted out, it said its own County General exemption would remain in place. A follow-up law, HB 92, lets a body that opted out reverse that decision by March 1 of each tax year from 2026 through 2029.

Because of those opt-outs, the school millage, which is the largest part of either bill, moves with assessed value on both sides of the line. The two school rates also differ. For 2026, the Cobb County School District adopted 18.70 mills, above the 18.016-mill rollback rate given in its tax notice. Marietta City Schools stayed at 17.97 mills, a plan WSB-TV reported in April and the county's final rate table confirms.

So the city side has the lower school rate and also a smaller part of the bill that is exposed to rising values. Before a sale, more of a long-time city owner's bill is frozen than a comparable owner's in unincorporated Cobb.

What happens to those frozen layers at closing

Since both exemptions end when the home sells, the sale itself changes how the bill is calculated. Neither freeze transfers to the buyer. A buyer who files for a homestead exemption starts a new freeze based on their own purchase. Under Cobb's rules, the base is the year before they became eligible, and Marietta's freeze is set at the purchase value.

Here is how that plays out. Say a seller has owned a city home for many years. Their city and county general lines are based on a value from long ago, and only their school line follows today's market. After the sale, all three lines are figured from current value. In unincorporated Cobb, a long-time owner's fire and school lines already follow current value, so the change after a sale is smaller and limited to the County General line. The longer the seller has owned the home, and the more its value has risen, the larger the reset tends to be inside the city.

None of this has to do with the rates themselves. The city held its rate flat, and the county kept its General rate at 8.46. The gap comes from the frozen base values that end with the sale.

Two bills, two deadlines

Inside the city there is also a timing issue. Cobb County bills county general, fire and school taxes, and the cities bill their own, so a home inside Marietta's limits receives two separate bills. For 2026, Cobb's bills were due October 15. The City of Marietta bill covers the city, Marietta City Schools, the Gateway Marietta CID and the Downtown Marietta Development Authority. The Cobb Courier reported that it was mailed starting August 26 with an October 31 deadline.

For a city home, the school tax is on the city bill and not the county bill. Someone who reads only the Cobb bill will miss the largest part of the tax. On a home in unincorporated Cobb, one county bill covers everything.

The rules above are general information, not tax, legal or financial advice. Exemption eligibility depends on your circumstances, so confirm your own situation with the Cobb County Tax Commissioner, the City of Marietta Tax Division, or your tax professional.

Questions buyers ask about the city line

Does the city charge a fire tax on top of its own millage?

No. The 2026 rate table lists no Cobb County Fire District levy for City of Marietta addresses, and the city's 4.692 mills is the only city millage on a standard city parcel. Unincorporated addresses pay the 2.97-mill county fire levy.

Are there other basic exemptions besides the freezes?

The Cobb Tax Commissioner lists a $10,000 basic homestead exemption that applies to county general and county school general taxes. Homestead requires that you own the home and live in it as your primary residence.

Do any non-tax charges change at the city line?

Stormwater is one. Cobb Water's rate schedule includes a $4.75 monthly residential stormwater fee for unincorporated Cobb and Mableton. Cobb does not charge that fee to customers inside Marietta city limits, because it does not provide stormwater service there. Trash service also differs. Cobb does not collect residential trash in unincorporated areas, where private haulers provide it, while Marietta Environmental Services serves the city.

Could the school freeze situation change?

HB 92 lets any body that opted out of HB 581 reverse its decision by March 1 of a given year from 2026 through 2029. Any change for a given year would be decided by that spring deadline.

When you're comparing a home inside Marietta's limits with one just outside them, Taylor can help you work out which parts of each seller's bill are frozen and which will start over at your purchase price, so your budget reflects what you'll actually pay. Schedule a consultation with HomesByTaylorRE.