A luxury mortgage is a home loan too large to be sold to Fannie Mae or Freddie Mac, and almost everything that distinguishes it from an ordinary mortgage follows from that. For 2026, the Federal Housing Finance Agency set the conforming loan limit at $832,750 for a one-unit property in most of the country, and up to $1,249,125 in designated high-cost areas; loans above it are called jumbo mortgages. Above the line, the lender keeps the loan on its own books or sells it to private investors, underwrites it with its own standards and prices it itself.
What the conforming limit actually limits
Each year, the FHFA sets the largest mortgage Fannie Mae and Freddie Mac will acquire, adjusting the baseline to reflect the change in average U.S. home prices. For 2026 the baseline is $832,750, up $26,250 from 2025, following a 3.26 percent rise in the FHFA house price index between the third quarters of 2024 and 2025. In areas where 115 percent of the local median home value exceeds the baseline, the limit rises with local values, up to a ceiling of 150 percent of baseline — $1,249,125 for 2026. Alaska, Hawaii, Guam and the U.S. Virgin Islands carry separate statutory figures: a $1,249,125 baseline and a $1,873,675 ceiling.
Three things follow from how the limit is built.
It limits the loan, not the home. The price alone does not make a mortgage jumbo; the balance does. A buyer who puts half the price down on a $4M home still borrows $2M, which is above the limit in every county. In the highest-priced markets — Manhattan, Beverly Hills and Bel Air — a price common for the area leaves a jumbo balance even with a substantial down payment.
The line is geographic. Two identical homes a few miles apart can sit in counties with different limits; most counties sit at the baseline, and whether a loan is jumbo depends on where the home is.
The line moves. The limit is re-set annually as home prices change, so "jumbo" drifts upward over time.
What changes when you cross the line
Below the line, a mortgage is a standardized product: a lender originates it to criteria set by Fannie Mae and Freddie Mac and sells it to them; the two enterprises pool such loans into mortgage-backed securities, and the lender's capital is typically committed only until the sale. Above the line, that route is closed. The Office of the Comptroller of the Currency describes the alternatives in its Mortgage Banking handbook: hold the loan in the bank's own portfolio, sell it directly to private investors, or place it into mortgage-backed securities the bank arranges itself. Which a lender uses, and on what terms, is its own decision — and its own risk.
The practical consequences:
| At or under the limit | Above the limit | |
|---|---|---|
| What it is called | conforming | jumbo — what "luxury mortgage" refers to |
| Who can buy the loan | Fannie Mae, Freddie Mac | the lender's own portfolio, or private investors |
| Who writes the underwriting rules | the enterprises' criteria, plus the lender's | the lender, within federal consumer rules |
| How pricing is set | for a standardized product | loan by loan; the CFPB notes it may be higher |
| Available structures | the enterprises' menu | the lender's own menu: fixed, adjustable, interest-only |
Because the lender is committing its own balance sheet, jumbo underwriting weighs the borrower more directly: the size of the down payment, documented income, credit history and the assets you hold after closing. One floor applies everywhere, whatever the loan size. Under the federal ability-to-repay rule, a lender must make a good-faith effort to determine that you can repay a consumer mortgage before making it. A private bank has room to weigh your balance sheet in ways a standardized program cannot, but it cannot skip that step.
Private banks and relationship pricing
At these loan sizes, the lenders doing the most business are often banks lending from their own balance sheet — frequently the private bank or wealth arm where a household already holds its assets. Because the bank keeps the loan, it can look at the whole relationship when it decides what to offer: mortgages, deposits, assets under management.
This is what "relationship pricing" means in practice, stated qualitatively because no two banks price alike. The interest rate, the fee structure and the willingness to lend a large sum quickly may all reflect the value of the relationship to the bank. That can be worth real money. It also has candid costs:
- The benefit is usually conditional. A bank's best terms may assume you hold a certain share of assets with it. Ask what the identical loan costs with and without moving assets, in writing.
- It concentrates your finances. The mortgage, the deposits and the portfolio at one institution make it a larger single point of exposure.
- Negotiated terms are hard to compare. A retail lender publishes a rate sheet; a private bank negotiates. Two written offers, read line by line, are the only reliable comparison.
- The value may not sit in the rate. Flexibility on structure, speed of approval or a larger loan can matter more than a small difference in interest, depending on the purchase.
None of this argues against private banks. It argues for treating a relationship offer like any other large financial commitment: on paper, beside at least one competing offer.
How private banking terms differ from retail
A retail jumbo — from a bank's mortgage division or a lender that specializes in large loans — is standardized. Rates and points follow published grids, the Loan Estimate format lets you compare offers, and underwriting runs from documented income, debts, credit and reserves. It behaves like a conforming loan with a larger balance.
A private-bank mortgage is negotiated. Underwriting can weigh the whole balance sheet: assets held at the bank, liquidity outside it, sometimes pledged collateral. Structures can be built to the borrower — interest-only periods, customized amortization, larger loans against complex income. The trade-offs are equally real: approvals can take longer, the pricing is opaque by design, and the bank expects the relationship to deepen. A private bank can decline a profile a retail lender would approve, and the reverse is also true; each lends where its own balance sheet is comfortable.
Two things do not change with the channel. Federal ability-to-repay requirements apply to consumer mortgages of every size. And the tax deduction is the same at a private bank as anywhere else: under IRS Publication 936 the deduction reaches interest on the first $750,000 of debt for loans taken out after December 15, 2017, or $375,000 if married filing separately. On a multimillion-dollar loan, most of the interest sits outside the cap.
Interest-only structures in the jumbo market
The structure most associated with large jumbo loans is interest-only. The CFPB defines an interest-only mortgage as one whose scheduled payments require only interest for a specified time. The balance does not fall, and when the period ends the choices are to repay it at once, refinance if refinancing is available, or begin monthly principal-and-interest payments that are higher. Interest-only is common above the conforming limit for a practical reason: the lender holds the loan, so it can offer structures the standardized market does not, and the typical borrower at these prices is asset-rich with uneven income. The cost is fixed by arithmetic. When amortization begins, the same balance is repaid over fewer years, so the payment steps up sharply — in the reference case used on this site, from $17,333 a month to $27,875 a month on $3,200,000 at an assumed 6.5% after fifteen interest-only years. How interest-only jumbo mortgages work works through the numbers and the planning question they raise.
The costs, candidly
Above the conforming limit, costs deserve the same attention as structure.
Interest dominates at these sizes. On a $4M loan over 30 years at an assumed 6.5%, the payment is $25,283 a month and the interest totals $5,101,780. The rate is an assumption for illustration, not an offer. The CFPB notes that the cost of a jumbo mortgage may be higher than the cost of a conforming one, and pricing varies lender to lender, so compare written offers.
The deduction is capped. The first year's interest on that loan is about $258,684. Under IRS Publication 936, the deduction reaches only the portion attributable to the first $750,000 of the balance. What the loan costs after tax is a question for your CPA, and the answer changes the real rate substantially at this size.
Reserves and down payment run larger. Lenders committing their own capital commonly ask for more of each; the requirements are set bank by bank, so ask early, because they shape how much capital stays liquid after closing.
Time is a cost. Portfolio underwriting can take longer than a standardized closing, which matters when a seller weighs your offer.
Where the program fits
The Family Office Mortgage is not a lender, a bank or a government program, and the mortgage it coordinates is not exempt from anything above: it is a third-party jumbo, underwritten in the usual way, subject to the same ability-to-repay rules and the same deduction cap. The program adds something around the loan rather than to it. Roughly half the purchase price is committed at closing — about 20% as the down payment and up to 30% as the contribution to a structured financial product whose projected payout, years later, is designed to make the payments.
In the $4M reference case, $2,000,000 is committed at closing, the payment is $17,333 a month for fifteen interest-only years, and from year 16 the payment is $27,875 a month with a projected payout of about $340,000 a year sized to the payment. The payout is a projection, not a guarantee, and the lender still qualifies you against the later payment in the usual way.
Relative to private-bank financing, the program does not compete with the lender; the lender can be yours or one the program introduces. What it competes with is the plan for the money: instead of holding assets at a bank to earn better loan terms, a qualifying household commits capital at closing so the later payments have a designed, funded source. The published criteria are a home of $4M or more, $5M or more in household assets not counting the home, and income of $500,000 or more; the eligibility page states them in full.
Candidly, it does not suit everyone. It asks for roughly half the price up front, which is the point of the design and also its cost. It suits a long horizon — the instrument needs about fifteen years before it is designed to fund the payments — so a home you may sell in a few years belongs in a plain jumbo. And if a private bank you already work with offers terms you prefer, weigh them in writing against the program's full path, year by year. The calculator runs the program's structure on your price.
