The short answer: when you sell for more than you paid (plus improvements), the profit is a capital gain. For a primary residence, a large exclusion — $250,000 if single, $500,000 if married filing jointly — shields most sellers from tax on that gain. Owners with very large gains, or those selling investment property, have more to plan for.
This is general information, not tax advice. Confirm your specifics with a CPA.
The primary-residence exclusion
If the home was your main residence for at least 2 of the last 5 years, you can generally exclude up to $250k (single) or $500k (married filing jointly) of gain from federal tax. Many Bay Area sellers fall entirely within this and owe nothing on the sale of a primary home.
When gains get big
Long-time owners can have gains that exceed the exclusion — decades of appreciation add up. The taxable portion above the exclusion is where planning matters. Your cost basis (what you paid plus qualifying improvements and certain selling costs) reduces the gain, so good records help.
Reporting the sale
Even if your entire gain is excludable, you generally still have to report the sale if you receive a Form 1099-S, Proceeds From Real Estate Transactions, from your title or escrow company. If any portion of the gain isn’t excludable, it’s reported on Schedule D and Form 8949 with your federal return. Your escrow company or CPA can confirm whether a 1099-S will be issued for your specific sale.
Options and related planning
- Investment property? The primary-residence exclusion generally doesn’t apply, but a 1031 Exchange Basics can defer the tax by reinvesting into another property.
- Over 55 and moving? Property-tax portability under “Prop 19 Move-Up Tax Savings” is a separate benefit worth understanding (it’s about your property-tax base, not capital gains).
- Your basis and prior taxes. Your Prop 13 assessed value isn’t your cost basis — see “Prop 13 Explained” to avoid mixing them up.
A simple example
Say a married couple bought a Fremont home decades ago for $300,000 and sells it today for $1,900,000, with $100,000 in qualifying improvements over the years documented in receipts and permits. Their cost basis is roughly $400,000, making their gain approximately $1,500,000. Filing jointly, they can exclude $500,000 of that gain, leaving roughly $1,000,000 potentially subject to capital gains tax — which is exactly the kind of number where working with a CPA before listing, not after closing, can materially change the outcome.
The bottom line
Capital gains are separate from your closing costs — both come out between sale price and take-home. See the full picture in Seller Net Proceeds Explained, and start the whole process from How to Sell Your Home in Silicon Valley.
For a capital-gains check alongside your net sheet, message Laxmi directly on WhatsApp — she’ll also point you to a trusted CPA where needed.
Official sources: IRS Topic No. 701, Sale of Your Home · IRS Publication 523, Selling Your Home
Wondering how a move affects your property tax base too? Try the Prop 19 Property Tax Calculator.
Laxmi Top Realtor · Intero Real Estate · DRE #02047105. Equal Housing Opportunity. Not tax or legal advice — consult a qualified professional.