How Much Cash to Keep After Buying a Home in SF

By Khaing Zin Thet, REALTOR® · Published October 26, 2026 · Sources: Fannie Mae Selling Guide, Freddie Mac

Ask a buyer how much cash they need and they'll usually answer with a down payment. It's the number every calculator asks for first. It's rarely the number that decides whether the purchase feels comfortable a year later.

Key takeaways

Plan for five layers of cash: down payment, closing costs, reserves, move-in costs, and a "surprise line" for things like special assessments.
Fannie Mae requires no minimum reserves for a one-unit primary home, but six months for a 2-4 unit primary home, and lenders can require more.
A lender's minimum isn't a recommendation. Size your own cushion to the building's risk and how steady your income is.

The better question is: how much cash will I have left after closing, and is that enough for this particular property?

Five layers of cash, not one

List these and put a number next to each before you start touring.

Down payment. The percentage you finance at. Your lender sets the minimums for your loan type.
Closing costs. Escrow, title, appraisal, lender fees and recording. Your lender's Loan Estimate itemizes them, and it's the only version of this number worth trusting. Ask for one early.
Reserves. Cash you keep after closing, measured in months of your total housing payment.
Move-in costs. Movers, deposits, appliances and the small repairs every inspection turns up.
The surprise line. For condos and TICs, a special assessment. For houses, the roof, sewer lateral or foundation item the inspection flagged as "monitor."

What lenders require, and what they don't

There's a floor, and it depends on what you're buying. Fannie Mae's Selling Guide (B3-4.1-01, updated August 7, 2024) sets no minimum reserve requirement for a one-unit principal residence underwritten through its automated system. It requires six months for a two-to-four unit principal residence, two months for a second home, and six months for an investment property.

That matters in San Francisco, where small multi-unit buildings are a common path to ownership. If you plan to live in one unit of a duplex or triplex, the minimum in that rulebook is six months of housing payments. Individual lenders can set their own requirements above Fannie Mae's, and many San Francisco purchases use jumbo loans that follow each lender's rules. Ask your loan officer which number applies to you.

One detail that surprises equity-heavy buyers: Fannie Mae doesn't count unvested stock or unvested restricted stock toward reserves. Only what you can actually access counts.

How to size your own number

Here's the arithmetic with a made-up payment, so you can swap in yours. If your all-in monthly housing payment (mortgage, property tax, insurance, any HOA dues) were $8,000, six months of reserves would be $48,000. That's an illustration of the formula, not a benchmark.

Then adjust for the property and for you:

Building risk. A condo or TIC with thin reserves of its own deserves more cushion than a well-funded building. The HOA's reserve study and meeting minutes tell you which one you're looking at.
Income shape. If a large share of your pay is bonus or equity that vests on a schedule, your worst year looks different from your average year. Test the payment against base pay alone.
Who bears the risk. In a house, you carry all repairs. In a condo, you share them with neighbors and a board. In a TIC, you share them with a small group under a private agreement.

The trade-off

More reserves means a smaller price, a smaller down payment, or a later start. Less cushion gets you in sooner and leaves you exposed to the first large bill. Neither is wrong. What matters is that you chose it on purpose, before you found a home you loved.

Rates add pressure here. Freddie Mac's weekly survey put the national average 30-year fixed rate at 7.32% for the week of October 22, 2026. That's a national average, not a quote. At that level, it's tempting to stretch the down payment to lower the payment; check what that does to your reserves first.

If a tailored version of this would help, reply with your timeline and the property type you're considering, and I'll help you put numbers to each layer.

Not legal, tax, or financial advice. This post is general education based on the sources below. Lending and tax questions belong with a licensed loan officer and a CPA.

Sources: Fannie Mae Selling Guide, B3-4.1-01, "Minimum Reserve Requirements" (08/07/2024). Freddie Mac, Primary Mortgage Market Survey (week of Oct 22, 2026).

Khaing Zin Thet | Vanguard Properties | DRE #02443950