Two Marietta houses on the same street can sell for the same price and still show very different annual tax amounts. Neither number tells a buyer what they will owe. In Cobb County, the property tax on a listing reflects how long the seller has owned the home and how old the seller is. Once the deed changes, most of that history is gone.
This comes from local rules that Cobb County and the City of Marietta chose to keep. Your budget for a Marietta home should start from them.
The freeze belongs to the owner
Cobb County has a floating homestead exemption that freezes a home's taxable value for as long as the owner lives there. The county's July 2026 millage presentation says it "locks your home's taxable value during ownership," so the owner sees "no tax increase from appreciation in home value." The City of Marietta has had its own version for 23 years. It freezes a home's taxable value "at the value when purchased."
Cobb's chief tax assessor, Stephen White, explained the scale of it at a December 2024 briefing that the Cobb Courier covered. "Our current float, that we have in Cobb County and in the cities, is a total freeze on the value," he said. According to the same report, every city in Cobb has a float except Austell and Mableton.
A freeze tied to a purchase or to a period of ownership ends when the owner sells. The Cobb Tax Commissioner's homestead application instructions tell owners to reapply for exemptions after a deed change or change in ownership. They also say the applicant must own the home, live in it and claim it as their legal residence on January 1 of the year they apply. When the seller's frozen value goes away, the buyer's starting point is the market as it stands at purchase.
How large the gap gets
Cobb County's own example shows the effect. The FY2026 millage presentation charts a homesteaded owner from 2018 through 2026 and says this person "would have paid $1,447.64 for County General without float," a difference of $838.22. That puts the county general line on that bill at about $609 in 2026, against about $1,448 for someone paying on current value. The current-value bill is roughly 2.4 times as large, and that is for one line of the bill.
The gap grows every year that values rise. Cobb's residential real property digest grew from about $44.80 billion in 2025 to about $46.68 billion in 2026, according to the same presentation. For a long-time owner, each year of growth is value that doesn't get taxed under the frozen lines. When the home sells, all of those years of growth become taxable at once.
The largest line doesn't freeze for most owners
This is the part that most often changes a buyer's monthly payment. Cobb County's float covers the county general fund. School taxes are taxed separately, and the school rate is the largest one on the bill.
| Levy | 2026 rate | How it treats a homesteaded owner |
|---|---|---|
| Cobb County general fund | 8.46 mills, adopted July 28, 2026 | Taxable value frozen during ownership; $10,000 basic homestead exemption |
| Cobb County School District general | 18.70 mills, adopted July 23, 2026 | $10,000 basic homestead exemption; owners 62 and older pay no school general or school bond tax |
| Marietta City Schools | 17.970 mills, adopted July 28, 2026 | Confirm exemption terms with the City of Marietta tax office |
| City of Marietta | Set by the city's FY2027 levy ordinance | Taxable value frozen at the value when purchased |
The Cobb Tax Commissioner's exemptions page describes the county school exemption for owners 62 and older as "an exemption from all taxes in the school general and school bond tax categories." Owners qualify if they turn 62 on or before January 1 of the tax year. The basic $10,000 homestead exemption covers the county general and county school general categories. The page lists no freeze for school taxes for owners under 62.
So a seller who has lived in an unincorporated Marietta home for years and is 62 or older can have a bill with a frozen county general line and nothing at all on the school line. A buyer under 62 pays the county general rate on today's value and the full school rate after the basic exemption.
A hypothetical example shows the scale. Cobb taxes property on an assessed value of 40% of fair market value, under Georgia law. A $500,000 home has an assessed value of $200,000. Subtract the $10,000 basic exemption and $190,000 is taxable. At the Cobb County School District's 18.70 mills, the school general line alone comes to about $3,553 a year. A seller who qualifies for the age-62 exemption would have had $0 on that line. That one line can be larger than the seller's whole bill.
A Marietta address doesn't tell you the tax district
The figures above assume unincorporated Cobb. Many homes with a Marietta mailing address are outside city limits, and many are inside them. Inside the city, the City of Marietta and Marietta City Schools levy taxes too, and their rules and rates differ from the county's.
Cobb's new home purchaser estimator asks you to enter a fair market value, choose a tax district "city or unincorporated," and select exemptions. The Tax Commissioner's FAQ also says the estimator "covers county taxes only; city taxes are excluded." For a home inside the city, the county estimate leaves out part of the bill. City exemptions go through the city as well. The Tax Commissioner says residents of a city "must apply for the city exemptions directly with the city tax office."
The city's freeze can work in a buyer's favor over time. Marietta says its freeze is more generous than the statewide alternative. In its example, a home starts at a $350,000 taxable value and gains 5% a year in market value. The city's version keeps the taxable value fixed, while the state version would let it rise with inflation. The same rule that resets the bill at purchase then holds the city's taxable value flat for as long as the buyer owns the home.
The 2025 state law didn't change any of this
Georgia's HB 581 created a statewide floating homestead exemption. It limits annual increases in taxable value to the inflation rate, unless a local government opts out. Cobb County, the City of Marietta, the Cobb County Board of Education and Marietta City Schools all opted out in early 2025. The Marietta City Council voted 7–0 on February 25, 2025, and Cobb commissioners voted 4–0 the same week. The Georgia Secretary of State's opt-out list shows filings from all four.
The county and city kept their own total freezes. Cobb's announcement said the county's existing exemptions, including the senior school-tax exemption, would not be affected. For school taxes, the opt-out means a homeowner under 62 has no statewide cap to fall back on.
These decisions can still change. A follow-up law, HB 92, lets opted-out jurisdictions reverse course for future years, with March 1 deadlines for tax years 2026 through 2029, WABE reported. The Secretary of State's list is the place to check a jurisdiction's current status.
The 2026 bill has a one-time credit
There's one more reason not to rely on a seller's recent bill. Cobb's 2026 bills, due October 15, show the state's Homeowner Tax Relief Grant as a separate reduction for qualifying homesteads. The Georgia Department of Revenue describes the grant as an $18,000 reduction in assessed homestead value under HB 439, which Governor Kemp signed May 12, 2026. The 2026 bill shows this credit, but nothing in the grant itself carries it into future years.
Getting a realistic number before you offer
- Find out whether the home is inside City of Marietta limits or in unincorporated Cobb.
- Run the purchase price through Cobb's new home purchaser estimator, with the correct district and only the exemptions you would qualify for.
- If the home is inside the city, contact the City of Marietta tax office for city and Marietta City Schools amounts and exemption terms, since the county estimator doesn't include them.
- Ask your lender to build escrow from that estimate. The seller's bill is the wrong starting point.
- Plan the homestead application. Cobb requires you to live in the home on January 1 of the year you apply, and you must apply by the appeal deadline printed on that year's Notice of Assessment. Late applications lose the exemption for that year. For 2026, Cobb's deadline was July 20.
FAQ
Does the seller's frozen value transfer to me? No. Cobb's float applies while the owner owns the home, Marietta's is set at the value when purchased, and Cobb asks new owners to reapply after a deed change. Your base starts with you.
Will my value stay frozen once I apply? For the Cobb County general fund and City of Marietta taxes, the local floats freeze taxable value while you own the home. Cobb school taxes have no freeze for owners under 62. Changes in tax rates and other levies can still move your bill.
Is the age-62 school exemption automatic? No. The Tax Commissioner requires proof of age with the application. You must be 62 on or before January 1 of the tax year.
This post is general information, not legal, tax or financial advice. Please confirm your own situation with the Cobb Tax Commissioner, the City of Marietta tax office, or a qualified tax professional.
If you're comparing Marietta homes and want to know what the taxes will actually be, the team at Strong Tower Realty can help you check a home's tax district and build a payment estimate from the purchase price instead of the seller's bill. Request a free home valuation or speak with a local agent today.
