Almost every home bought for $4M or more in Miami Beach or Coral Gables is financed with a jumbo or super-jumbo mortgage, because Miami-Dade County's 2026 conforming loan limit is $832,750 — the national baseline, not a high-cost figure. In 2026 the buyer of a $6,000,000 home here, with $5M or more in assets apart from the home, usually weighs three paths: pay cash, take a conventional jumbo from a private lender, or use a structure such as The Family Office Mortgage, which pairs an interest-only jumbo with a structured financial product whose projected payout is sized to the later payments.
Why nearly every purchase here is a jumbo loan
Each year the Federal Housing Finance Agency sets the largest loan Fannie Mae and Freddie Mac may buy. For 2026 the baseline for a one-unit home is $832,750, and the most expensive markets reach a ceiling of $1,249,125. Miami-Dade County sits at the baseline on the FHFA's county-by-county list: $832,750 for a one-unit home in 2026. The only Florida county above the baseline is Monroe, the Keys, at $990,150. The state's most expensive market is, by federal measure, not a high-cost area.
The practical effect is that any loan above $832,750 is a jumbo, priced and underwritten by the lender that keeps it rather than sold to the agencies. On a $6,000,000 home with 20% down, the $4,800,000 loan is 5.8 times the county limit, deep in super-jumbo territory where each lender writes its own terms. Whether the home is an estate on Coral Gables' bayfront streets or a full-floor residence on the Miami Beach islands, the mortgage is negotiated with private credit, and the seller's side of the table knows it.
How buyers here actually finance
Cash is a real competitor at this price point. It brings certainty and speed, and in a multiple-offer situation certainty can matter as much as price. What it costs is everything else: liquidity locked in one asset on one street, and — if the cash is raised by selling appreciated holdings — a capital gains tax bill that never appears on the closing statement. Paying cash versus financing works through that trade.
The conventional alternative is a jumbo from a private lender, and the common version at this level is the interest-only jumbo mortgage: pay interest for a set period, then principal and interest over what remains. Lenders weigh the down payment, documented income, and the liquid assets left after closing; for households whose wealth sits in a business or a portfolio rather than a pay stub, assets can carry as much of the qualification as income does. One rule matters for planning: the lender judges your ability to repay against the later, larger payment, not the interest-only one.
At an assumed 6.5% — the rate this site uses for illustration, not an offer — a 30-year fully amortizing loan on $4,800,000 runs $30,339 a month. An interest-only loan runs $26,000 a month for the first fifteen years, with the balance unchanged, then $41,813 a month for years 16 to 30, a step of 60.8%. The interest-only version costs more interest in total and frees more capital each month.
Between the two, many buyers here borrow against what they already own rather than sell it, keeping the portfolio intact and funding part of the purchase with a securities-backed line. Buy, borrow, die, and where the home fits covers that route, including its main exposure: the line is tied to market value, and a fall in the account can bring a maintenance call.
The local costs that change the math
Documentary stamp taxes
Florida taxes the documents themselves. On a deed, the state rate is 70 cents per $100 of the price in every county except Miami-Dade, where it is 60 cents; Miami-Dade adds a surtax of 45 cents per $100 that is not due when the deed transfers only a single-family home, according to the Florida Department of Revenue. On a $6,000,000 purchase the deed tax is $36,000 on a Coral Gables estate home, or $63,000 on a Miami Beach condo. The mortgage is taxed separately at 35 cents per $100 of the amount secured, with no cap — $16,800 on a $4,800,000 loan — while the note itself carries the same 35-cent rate capped at $2,450. Florida law makes every party to the document liable; the purchase contract decides who actually writes each check.
Property taxes
Florida property taxes are set locally on assessed value, and a Miami-Dade bill depends on the municipality, the school district and the exemptions a household claims. Florida's assessment limits hold long-owned homes at values far below market, which is why a neighbor's bill misleads: the buyer's assessment resets to market value at purchase. Model the actual bill for the specific address, with your CPA, rather than an average rate from an article. Florida's lack of a personal income tax is the other half of the ledger.
Condominium safety and reserves
Since Florida's 2022 building-safety law — Chapter 2022-269, Laws of Florida, passed after the Surfside collapse — condominium buildings three stories or higher must undergo milestone inspections by December 31 of the year the building turns 30, or 25 if it stands within 3 miles of the coastline, and every 10 years thereafter. Associations must complete a structural integrity reserve study at least every 10 years, and from December 31, 2024, owners can no longer vote to waive or reduce reserves for the structural items the study lists. For a Miami Beach condo buyer the practical read is direct: the older towers are being engineering-audited, reserve funding is no longer optional, and the association's budget now deserves the same diligence as the view. Lenders and their appraisers read the same association documents.
Wind and flood coverage
Miami Beach and the coastal stretches of Coral Gables are priced for weather. Wind and flood coverage on the coast runs materially higher than inland buyers expect, and the figure belongs in the affordability math next to the mortgage payment: a lender will require flood coverage for a home in a designated high-risk flood zone, and on the barrier islands elevation and construction decide what coverage costs. Two similar condos can carry very different charges. Get the actual figure for the specific address before you set your price.
Where the program fits
The Family Office Mortgage is built for this price range: homes of $4M or more, households with $5M or more in assets not counting the home, and $500,000 or more in income, as set out on the eligibility page. On a $6,000,000 purchase it commits about half the price up front — $1,200,000 as the down payment and $1,800,000 as the contribution to a structured financial product, $3,000,000 in total — against $6,000,000 to pay cash or $1,200,000 down on a conventional jumbo. What a Family Office Mortgage is explains the structure in full.
The mortgage itself comes from a third-party lender and is unchanged by the program: a jumbo, interest-only for the first fifteen years, then principal and interest. At an assumed 6.5%, the payment on the $4,800,000 loan is $26,000 a month for years 1 to 15, then $41,813 a month for years 16 to 30. The financial instrument's projected payout is sized to that later payment, and the plan is reviewed every year against the schedule. The payout is projected, not guaranteed, and the lender still qualifies you against the later payment in the usual way.
Who it suits here is candid. It fits the buyer of a $6,000,000-plus island condo or Gables estate who would otherwise pay cash, prefers to keep half the capital working, and intends to hold the home long enough — roughly fifteen years — for the instrument to build. It does not fit a buyer stretching to qualify, a short hold, or a household that would rather put 20% down and keep the rest uncommitted. That buyer already has a good product available: the conventional jumbo.
The comparison shows the program against a conventional jumbo year by year, and the calculator runs the numbers on the price of the home you have in mind.
