How to Appeal Your Cobb County Property Tax Assessment (and When It's Worth It)

Cobb County markets itself, fairly, as one of the cheaper places to own a home in metro Atlanta: a county government that held its millage flat again in 2026, a homestead freeze that predates the state's new cap by decades, and a school tax exemption at 62 that's the most generous in the region. All true. And yet when Cobb over-values a home, most owners still pay real money for it, because the freeze and the senior exemption each cover exactly one slice of the bill, and the biggest slice belongs to neither.

This guide lays out how a Cobb County property tax appeal works: the calendar, what the freeze actually locks, who has genuine money at stake, what an appeal realistically saves at current rates, and how to be ready for the 2027 notice now that the 2026 window has closed.

The Cobb calendar: notices in early June, 45 days to act

The Cobb Board of Tax Assessors mails Annual Notices of Assessment in late spring; in 2026 they went out on June 5. Georgia law gives you 45 days from the date printed on your notice to file an appeal, which put most 2026 Cobb deadlines around July 20. That deadline is a wall: miss it and you're locked into the county's number for the year, however wrong it is.

If you're reading this after late July 2026, this year's window has closed. Appeals already filed keep moving; new ones can't start until the 2027 notices land, likely late spring 2027 on Cobb's usual rhythm. When yours arrives, go by the printed date on it, not by any calendar rule of thumb.

How a Cobb tax bill is actually built

Georgia taxes property on its assessed value, which is 40% of fair market value. Your bill is that assessed value, minus exemptions, times each authority's millage. Cobb's 2025 adopted rates, which the county held unchanged for 2026:

• County General Fund: 8.46 mills. This is the line the homestead freeze covers.
• Fire fund: 2.97 mills (unincorporated and most areas without city fire service).
• Cobb County Schools: 18.70 mills. The biggest line on the bill by far, roughly 62% of a typical unincorporated total. No school bond levy on top.
• City line if you're in one: Marietta about 2.9 plus a 1.8 bond, Smyrna about 9, Kennesaw about 7.8 plus bond, and Marietta residents pay Marietta City Schools (about 18 mills) instead of Cobb Schools.

All in, an unincorporated Cobb homeowner faces roughly 30 mills before exemptions. Where that lands on you personally depends entirely on which protections you hold, so let's take them one at a time.

What the Cobb freeze really covers

Cobb's local floating homestead exemption is a genuine freeze: once you qualify for homestead, the taxable value on the covered line is locked at its level when you qualified, not just capped at inflation. It's the reason Cobb County government opted out of the state's HB 581 floating cap in 2025; the county's own freeze is stricter.

But read the county's description closely and the boundary is clear: the freeze applies to the county General Fund M&O line. It does not cover the school line, and Cobb's cities run their own separate city-line freezes (every Cobb city except Austell and Mableton has one, per the county's chief appraiser). So the freeze protects about 8.46 mills of a roughly 30-mill bill.

Also worth knowing: the basic homestead exemption itself is modest, $10,000 of assessed value off the county general and school general categories, worth about $272 a year at current rates by the county's own math.

The age-62 school exemption: the real Cobb superpower

At age 62, Cobb homesteaded owners qualify for a complete exemption from school taxes, both school general and school bond categories, with no income limit. It's the most generous senior school exemption in metro Atlanta and it removes the single biggest line from the bill. (Applications are due April 1 with the Tax Commissioner; it does not apply automatically when you turn 62.)

The honest flip side: this exemption defines who an appeal helps. If you're 62 or older with the school exemption and the county freeze, most of your bill no longer responds to your assessment at all, so a value appeal usually moves very little for you. If you're under 62, the opposite is true: the school line is your biggest exposure, it rides your full current assessment every year, and no freeze touches it.

Where a Cobb appeal actually pays

Per-line arithmetic, at 2025 adopted rates (held for 2026), rounded. Every $100,000 of over-assessment corrected is $40,000 of assessed value.

And for higher-value homes, East Cobb estates and the like: mass appraisal models struggle most with unusual and luxury properties, and Georgia law entitles you to an assessment uniform with comparable neighbors, a distinct legal ground that often fits these homes better than a pure market-value case. See our uniformity appeal guide.

2027 raises the stakes

In 2025, Cobb County, the Cobb County School District, and Marietta City Schools all opted out of HB 581's statewide inflation cap, each pointing to existing local protections. That era is ending: SB 33, passed in 2026, makes the statewide floating homestead cap mandatory beginning with tax year 2027, schools included.

A cap limits how fast a homesteaded taxable value grows from its base. It does not fix a base that starts too high, and it does nothing for non-homestead property. State guidance ties cap bases to final assessed values, and values established by appeal feed that base; the county-level mechanics for 2027 are still being implemented. The practical read for Cobb owners under 62 is simple: the value on your books going into 2027 is the one the cap will grow from, so the 2027 notice is the one to get right.

How the appeal process works in Cobb

The legal framework is statewide, and our step-by-step appeal guide covers the stages in depth. The Cobb specifics:

• File within 45 days of your notice date with the Cobb Board of Tax Assessors. Online filing at assessor.cobbcounty.gov is the cleanest path and gives you a timestamp; mail and in-person work too.
• Pick your forum: Board of Equalization (free, trained citizen panel, right for most homes), nonbinding arbitration, or a hearing officer for non-homestead property over $500,000. Superior Court, with an attorney, comes after if needed.
• Bring evidence, not frustration: comparable sales that closed before January 1 of the tax year, a recent purchase below the county's value, property record errors, and uniformity data on similar homes. Our comps guide shows how to pull sales that hold up.
• The payoff: a successful appeal generally locks your value for the appeal year plus two more under O.C.G.A. 48-5-299(c). In Cobb that means three years of protection on the school line, the exact line the freeze never covered. Details in our 3-year freeze guide.

Do you actually have a case?

Plenty of Cobb assessments are fair, and if yours is one of them we'd rather say so than file a long shot. If your fair market value is close to what your home would honestly sell for, and similar homes nearby are assessed on the same standard, skip the appeal and keep your Saturday.

You likely do have a case if any of these are true:

• Your value jumped sharply while comparable homes nearby sold for less than your new number before January 1.
• You recently bought for less than the county's fair market value in an ordinary, arm's-length sale.
• Your property record has errors: overstated square footage, a finished basement you don't have, condition the county hasn't seen.
• Near-identical neighbors are assessed lower per square foot than you for no clear reason.
• You hold the property without a homestead exemption (rental, LLC, second home), where every dollar of over-assessment hits at full millage, every year.

The honest Cobb bottom line

Cobb treats homeowners gently by metro standards: flat county millage, a real freeze on the county line, and a senior school exemption with no income test. But the freeze covers about a quarter of the typical bill, the senior exemption starts at 62 and not a day sooner, and the school line in between is the largest number on the page, riding your full assessment every year. If that assessment is wrong, you're overpaying on the exact line nothing protects, and from 2027 the new statewide cap will grow from whatever value is on your books. One correction, compounded for years. The first step is knowing whether your number is wrong, and that's a question we can answer for free next June.