Buying a Home in St. Johns County? Here’s How Property Taxes Are Calculated
One of the most common questions buyers ask is: “What will my property taxes be?”
The answer is not always reflected in the seller’s current tax bill. In Florida, property taxes can look very different after a sale—especially when comparing a local move-up buyer with someone relocating from another state.
Let’s look at both scenarios using a hypothetical $2.5 million home purchase in St. Johns County.
First, the Basics
Florida property taxes are based on three primary components:
- Just or market value: The value assigned by the county property appraiser
- Assessed value: The value after any Save Our Homes benefit or portability is applied
- Taxable value: The assessed value after homestead and other eligible exemptions
That taxable value is then multiplied by the property’s millage rate. One mill equals $1 in tax for every $1,000 of taxable value.
For this example, we are using a millage rate of 13.4686, the current certified rate for many unincorporated areas of St. Johns County. Rates can vary by taxing district, municipality and community.
Why the Seller’s Current Tax Bill Can Be Misleading
When a property transfers ownership, the previous owner’s homestead exemption and accumulated Save Our Homes assessment benefit do not remain with the property.
The home is reassessed at its current “just,” or market, value for the following tax year. Although that value is not automatically required to equal the purchase price, St. Johns County recommends using the purchase price when estimating a buyer’s future taxes.
If a home is purchased after January 1, the tax bill for that calendar year is generally still based on the seller’s existing assessment. The reassessment typically appears the following tax year.
Scenario One: An Out-of-State Buyer
An out-of-state buyer purchasing a $2.5 million home does not bring an existing Florida Save Our Homes benefit with them.
For estimating purposes:
- Purchase price/estimated market value: $2,500,000
- Estimated taxes before homestead: $33,672
- Estimated taxes with the current homestead exemption: $33,145
- Estimated monthly equivalent: $2,762
Florida’s 2026 homestead exemption totals $51,411. The first $25,000 applies to all property taxes, including school taxes. The additional $26,411 applies to non-school taxes.
At this price point, the immediate homestead savings is approximately $527 per year. However, the greater long-term benefit is the Save Our Homes assessment limitation.
Once homestead is established, annual increases in the home’s assessed value are generally limited to 3% or the change in the Consumer Price Index, whichever is lower. Over time, this can create a meaningful difference between the home’s market value and its taxable assessed value.
An out-of-state buyer should therefore budget based on the purchase price rather than the seller’s current tax bill.
Scenario Two: A Local Move-Up Buyer
A homeowner moving from one Florida homestead to another may be able to transfer—or “port”—their accumulated Save Our Homes benefit.
Portability is calculated by subtracting the current home’s assessed value from its just or market value. Up to $500,000 of this difference may be transferred to a new Florida homestead.
For example, assume a St. Johns County homeowner is selling a property with:
- Current market value: $1,500,000
- Current assessed value: $1,000,000
- Accumulated Save Our Homes benefit: $500,000
If that homeowner purchases a new residence for $2.5 million, the full $500,000 benefit may be portable because the buyer is moving to a more valuable home.
The estimated calculation would be:
- New home’s market value: $2,500,000
- Less portability benefit: $500,000
- New assessed value before homestead exemption: $2,000,000
- Estimated annual taxes with portability and homestead: $26,410
- Estimated monthly equivalent: $2,201
In this example, portability creates estimated annual savings of approximately $6,734 compared with an out-of-state buyer purchasing the same home.
Comparing the Two Buyers
$2.5 Million Purchase | Out-of-State Buyer | Local Move-Up Buyer |
|---|---|---|
Estimated market value | $2,500,000 | $2,500,000 |
Illustrative portability benefit | $0 | $500,000 |
Estimated assessed value | $2,500,000 | $2,000,000 |
Estimated annual tax with homestead | $33,145 | $26,410 |
Estimated monthly equivalent | $2,762 | $2,201 |
The local buyer’s actual savings will depend on the portability amount accumulated on the previous Florida homestead. Not every move-up buyer will have the maximum $500,000 benefit.
Portability must generally be transferred within three tax years, and buyers must apply for it—it does not transfer automatically.
Don’t Forget Non-Ad Valorem Assessments
Some tax bills also include non-ad valorem charges that are not based on property value. These may include:
- Solid-waste collection and recycling
- Community Development District fees
- Stormwater or special district assessments
- Other property-specific charges
These amounts appear separately on the property’s tax bill and are not reduced by the homestead exemption. They should be reviewed for every property being considered.
What About Florida’s Proposed Property-Tax Changes?
Florida voters are expected to consider a proposed constitutional amendment in November 2026 that could increase the homestead exemption for non-school property taxes.
However, the proposal is not currently in effect and would require approval from at least 60% of voters. It also includes a proposed five-year residency requirement before certain new Florida residents could receive the expanded exemption.
Until the measure is approved and its final rules are established, buyers should budget using the current property-tax system and treat any future changes as potential additional savings.
The Bottom Line
For an out-of-state buyer, the safest approach is to estimate future taxes using the anticipated purchase price and current millage rate.
For a local Florida homeowner, it is important to review the existing home’s TRIM notice and determine whether a Save Our Homes portability benefit can be transferred. For move-up buyers, that benefit can result in substantial annual savings.
Property taxes are property- and buyer-specific. As part of the home-buying process, I help my clients review the applicable tax district, estimate the post-sale assessment, identify non-ad valorem charges and account for any available portability before making a purchasing decision.
These examples are estimates based on a $2.5 million purchase, a millage rate of 13.4686 and 2026 homestead rules. Actual assessments, millage rates, exemptions and non-ad valorem charges may vary. Buyers should verify their individual eligibility with the St. Johns County Property Appraiser or a qualified tax professional.
Sources: St. Johns County Property Appraiser—Estimating Property Taxes and Homestead Exemption and Portability.