Jumbo Loan Microstructure

Once your loan balance crosses the FHFA conforming loan limit, you leave the Fannie/Freddie ecosystem entirely. The 2026 baseline conforming limit is $832,750 for one-unit homes nationally, and the high-cost-area ceiling — 150% of the baseline in the contiguous states — is $1,249,125, which is where Santa Clara, San Mateo, San Francisco, Los Angeles, and Orange counties sit. Reaching the ceiling is not automatic in an expensive metro: New York City’s five boroughs are capped at $1,209,750. Alaska, Hawaii, Guam, and the U.S. Virgin Islands run on a separate schedule whose baseline equals the mainland ceiling and whose own ceiling is $1,873,675; in practice only Maui and Kalawao counties clear $1,249,125 for 2026, at $1,299,500. Puerto Rico and the Northern Mariana Islands are not in that group and sit at the mainland baseline. FHFA resets these every November off its own house price index, so check the current year’s FHFA limits before relying on any specific number. Above those thresholds you are in Jumbo territory, and the rules change in ways that matter more than the headline rate:

Portfolio lenders versus the GSEs

Jumbo loans are not sold to Fannie or Freddie. They sit on the originating bank’s own balance sheet (the “portfolio”) or are placed into a private-label securitization. The lender is taking the credit risk, so the lender writes the rules. Private banks — JPMorgan, Bank of America Private Bank, First Republic’s successor franchises, Morgan Stanley, Goldman — price these loans against the rest of the relationship: assets under management, deposits, brokerage balances. Bring more, pay less.

Liquidity reserves in place of PMI

Portfolio lenders generally do not require PMI even at loan-to-value ratios above 80%. What they substitute is a post-closing liquidity reserve requirement: a stated amount of PITI (principal, interest, taxes, and insurance) that must remain in liquid or near-liquid accounts after closing, untouched and verifiable. Typical bands: 6 months of PITI on a modest Jumbo, 12 months as balances rise, and 18–24 months once loan size crosses roughly $2–3 million. Verify the specific number in writing with the lender before counting on it; banks tighten these in any credit contraction.

Asset-depletion underwriting

If your W-2 income is light relative to the loan you want (common for early-retirees, equity-heavy founders, or anyone living on portfolio distributions), Jumbo lenders will often qualify you on an asset-depletion basis: a stated fraction of your liquid investable assets, amortized over the loan term, counts as imputed monthly income for DTI purposes. The fractions vary — often 70% of brokerage and 100% of cash, divided by 240 months for a 20-year amortization, or by the remaining mortgage term — and again are negotiated against the relationship. Fannie runs a far narrower version of the same idea in Selling Guide B3-3.4-06, and the differences explain why this is a Jumbo conversation. Conforming counts only employment-related assets — retirement accounts you have unrestricted access to, a documented severance or lump-sum distribution — and leaves out, by omission rather than by name, ordinary brokerage holdings, stock options, unvested restricted stock, inheritances, sale proceeds, and virtual currency. Net of any early-distribution penalty and of the funds consumed at closing, the balance is divided by the full amortization term rather than 240 months, and the loan is capped at 70% LTV, or 80% if the owner of the assets is at least 62 at closing. An equity-rich founder in their forties gets nothing from the conforming version and everything from the private bank.

Relationship pricing

On a Jumbo of $1M+, the rate spread between a cold-call retail quote and a relationship-priced quote from a private bank where you already custody seven-plus figures is routinely 25–75 basis points. Over a 10-year hold, that is real money. Get a quote from your existing private-banking relationship before shopping elsewhere; if you don’t have one and you’re financing a large purchase, opening the relationship may pay for itself in the spread alone.

Documentation depth

Jumbo underwriters look harder. Expect two years of tax returns (often three), full schedules including K-1s, statements for every account showing reserve compliance, signed CPA letters for self-employed income, and an explanation for any irregular cash movement. Plan the document-gathering early — the documentation timeline is the primary bottleneck, not the rate.

The right way to think about Jumbo underwriting: the bank is making a relationship-based credit decision dressed up as a real-estate loan. Your job is to make the relationship part work for you on price, while keeping enough genuine liquidity outside the reserve requirement that the loan does not become the thing that constrains the rest of your financial life.