Every August, a document arrives in Miami-Dade mailboxes that most homeowners file away without a second look. It is the TRIM notice — short for Truth in Millage — and it is the first public look at what the Miami-Dade Property Appraiser's office thinks a property is worth. That value, not the tax bill itself, is the number that sets the stage for everything a homeowner pays later in the year.
The property appraiser does not set tax rates and does not collect taxes. The office's job is narrower and, in practice, more consequential: it assigns an assessed value to every parcel in the county, applies the exemptions a homeowner qualifies for, and certifies those figures so taxing authorities can set their rates against them. Understanding how that value is built — and reading the TRIM notice line by line — is the practical starting point for any homeowner who wants to question it.
The timing matters because the property appraiser's number feeds directly into the budget season now underway at City Hall. According to the City of Miami's official notices, the City Commission has scheduled its first budget hearing for September 10, 2026, and its second for September 24, 2026, both at 5:05 p.m. in the chambers at Miami City Hall, 3500 Pan American Drive. Those hearings are where the city sets its rate against the values the appraiser has certified — which is why the TRIM window, not the tax-bill window, is when a homeowner's input can still change the math.
What does the property appraiser actually do?
The Miami-Dade Property Appraiser is an elected constitutional officer whose office values real property for tax purposes. Under Florida law, the office determines the just — or market — value of each parcel annually, based on conditions as of January 1 of the tax year. It then applies any cap on increases for homesteaded properties, subtracts approved exemptions such as the homestead exemption, and produces the assessed value that appears on the TRIM notice.
The office also administers those exemptions. It decides whether a homeowner qualifies for the homestead exemption, processes portability of accumulated benefit when a owner moves within Florida, and handles classifications for agricultural or other special-use land. In short: the appraiser builds the base; the taxing authorities — the county, the city, the school board, and special districts — decide how much revenue to draw from it.
That division of labor is the single most useful thing a homeowner can keep straight. A high assessed value does not mean the appraiser raised anyone's taxes. It means the base grew. What happens next depends on the rates each governing body adopts, and on the exemptions and caps already on the property's record.
How is an assessed value actually set?
Florida requires the appraiser to use accepted appraisal approaches: comparing recent sales of similar properties, analyzing what it would cost to replace the improvements, and, for income-producing property, capitalizing the income it generates. For most single-family homes and condos, the sales-comparison approach carries the most weight — the office looks at what comparable properties in the area sold for and adjusts for differences.
Two Florida-specific rules shape the result for homeowners. First, the assessed value of a homesteaded property cannot rise by more than the cap Florida law sets each year, or by the percentage change in the consumer price index, whichever is lower — so a long-owned home's assessed value often sits well below its market value. Second, when a homesteaded property sells, the assessed value resets toward market value for the new owner. Buyers frequently see a jump in their first full tax year for exactly this reason, not because of any mid-year action by the appraiser.
Because the January 1 valuation date governs, the value on a given TRIM notice reflects the market as it stood at the start of that year — not the market as it looks when the notice arrives in late summer. That gap is worth remembering before reacting to the number.
What is on a TRIM notice, line by line?
The TRIM notice is not a bill, and it says so. It is an estimate of what the bill could look like under several scenarios. Reading it in order makes it manageable:
- Market value and assessed value. The notice shows the just or market value, then the assessed value after the homestead cap is applied. The difference between those two lines is the accumulated benefit a long-time owner is protecting.
- Exemptions. Each exemption the property receives is listed with its dollar effect. A missing homestead exemption here is one of the most common and most fixable problems — it means the owner never applied or the eligibility lapsed.
- Taxing authorities and proposed millage rates. The notice lists every body that taxes the parcel — county, school board, city, water management and other districts — with its proposed rate. A millage rate is the tax per $1,000 of taxable value; a rate of one mill means one dollar per $1,000.
- Estimated taxes under three scenarios. The notice projects the bill if rates stay the same, if the taxing body rolls its rate back to roughly the prior year's revenue level, and if the body adopts no increase over its rolled-back rate. The law requires each authority to hold a public hearing before adopting its final rate, and the notice lists those hearing dates.
The most common misreading is comparing this year's estimated tax to last year's bill and concluding the appraiser raised it. The change can come from any of three places: the assessed value, the exemptions, or the rate each authority adopts. The TRIM notice separates those, which is precisely why it is worth reading rather than filing.
What can a homeowner do about a value they disagree with?
The review process runs on a fixed calendar, and the TRIM notice states the deadline for formal action. A homeowner who disputes the value has two main routes.
The first is informal: contact the property appraiser's office, ask how the value was derived, and present evidence — recent sales of comparable properties, condition issues the office may not know about, or documentation of factors that reduce marketability. Offices routinely adjust values at this stage without any formal proceeding.
The second is formal: petition to the county's Value Adjustment Board, an independent body that hears assessment challenges. The petition window opens when the TRIM notices are mailed and closes on a stated deadline — typically 25 days after the mailing date under Florida's statutory framework — so the notice itself should be checked for the exact date rather than relying on memory. Filing a petition preserves the challenge regardless of whether the informal conversation resolves it.
One caution belongs here. Challenging an assessment is a question of value, not of tax rates or of a governing body's budget decisions. The Value Adjustment Board can lower an assessment; it cannot lower a millage rate. Homeowners who object to the rate side of the equation have a different avenue — the public budget hearings each taxing authority must hold before adopting its final rate, where testimony is taken on the record.
What this means for Miami-Dade homeowners
Our analysis of how the pieces fit together points to a simple sequence. Read the TRIM notice when it arrives, not after the bill does. Check the exemption lines first, because a lapsed exemption is the cheapest problem to fix. If the market value looks wrong, gather comparable sales and start with the appraiser's office before the petition deadline stated on the notice. And if the concern is the rate rather than the value, plan to speak at the taxing authority's budget hearing instead. Readers following this should also see Miami's Summer at City Hall Points to a November Bond Vote and a Budget Fight.
Budget season in Miami gives that last step real weight this year. The city's budget deliberations, already scheduled for two September hearings at City Hall, sit downstream of the values the appraiser has certified — and the coverage of Mayor Higgins ordering a line-by-line look at a city budget that doubled shows how much rides on the numbers. Homeowners who understand which office controls which lever can engage the right one at the right time. We covered a connected angle in Mayor Higgins Orders a Line-by-Line Look at a City Budget That Doubled.
What remains genuinely uncertain for any individual property is the final rate each authority adopts and the outcome of any appeal. The TRIM notice frames the question; the hearings and, where needed, the Value Adjustment Board answer it. The homeowner's job is to keep the two questions separate and act inside the notice's stated deadlines, which change from year to year and should always be confirmed against the current notice and the office's published instructions.