The San Mateo County housing market in 2026 tells a tale of two markets: soaring single-family homes and struggling condos. With single-family homes reaching a median of $1.93M (up 7% year-over-year) while condos and townhomes plummet to $830K (down 9%), the Peninsula is experiencing the most dramatic market bifurcation in a decade. Atherton's ultra-luxury segment is even wilder—homes above $25M are generating multiple offers in days. Meanwhile, the biotech corridor in South San Francisco, anchored by Genentech and a sprawling network of life sciences companies, continues to fuel demand for mid-market homes in San Carlos, Redwood City, and beyond.
This comprehensive guide covers the February 2026 data, city-by-city breakdowns, employment trends reshaping the market, and how much you're really paying in commissions when you sell.
The Big Picture: A Bifurcated Market
San Mateo County's overall median home price sits at $1.6M as of February 2026, down 8.4% year-over-year. But that aggregate number masks the real story: single-family homes are thriving while condos are cratering.
Single-Family Homes: Up and Overbidding
- Median price: $1.93M (up 7% YoY)
- Price per square foot: $1,070/sqft (up 2.1% YoY)
- Sale-to-list ratio: 106.9% (overbidding is alive)
- Days on market (DOM): 9 median, 19 average
- Inventory: 0.9–2 months supply
- Q4 2025 performance: +4.3% YoY
Single-family homes are the darling of the Peninsula. Buyers are still competing fiercely, with homes regularly selling above asking price. The tight inventory—fewer than 1,000 homes for sale across the entire county (out of 740,000 residents)—means any decent SFH gets multiple showings and offers within days.
March 2026 closed sales paint a vivid picture: 310 single-family homes sold at a median of $2.18M, with an average days-on-market of 12 days. For sellers, this is gold. For buyers, it's a sprint.
Condos & Townhomes: A Cautionary Tale
- Median price: $830K (down 9% YoY)
- Sale-to-list ratio: 99.6% (selling at or near asking)
- Days on market (DOM): 12 median, 23 average
- Inventory: 2.1 months supply
- March 2026 sales: 87 condos at $946K median
Condos are struggling. The 9% price decline, combined with longer marketing times and sales landing exactly at asking price (no bidding wars), suggests buyer fatigue in this segment. Condo owners who purchased during the 2022–2023 mini-boom are seeing equity erosion. This is the segment where first-time homebuyers and downsizers are hitting resistance.
The stark contrast is worth understanding: if you own a single-family home on the Peninsula, you're sitting on appreciating wealth. If you own a condo, you're treading water.
City-by-City: Where the Money Is
San Mateo County spans 27 communities, from ultra-luxury Atherton to the working-class charm of South San Francisco. Here's where the market stands in each key city:
Atherton: Luxury on Steroids
- Median price: $10.95M (March 2026)
- Ultra-luxury ($20M+): Multiple offers standard
- Buyer profile: Tech executives, venture capitalists, established wealth
Atherton is the crown jewel of Bay Area residential real estate. In March 2026, the ultra-luxury segment ($20M–$50M) is white-hot. Homes that would have taken 30+ days to sell in 2022 are now generating 2–4 offers within a week. The catalyst? Meta's Menlo Park headquarters employs 20,000+ people, many of whom are cashing out equity and upgrading to Atherton's grand estates. A recent listing at 28 Atherton Road (4.8 acres, modern estate) received 3 offers at $24.5M on day 10.
Menlo Park: The Meta Effect
- Median price: $2.8M (up 32.4% YoY)
- YoY growth: The highest in the county
- Buyer profile: Meta and Google engineers, startups cash-outs
Menlo Park's 32.4% year-over-year appreciation is the most dramatic in San Mateo County. Meta's financial performance and aggressive hiring (before the 2026 layoffs of 318 positions) have created a wealth effect that's driving competition in Menlo Park's premium neighborhoods. Properties on Santa Cruz Avenue and near Menlo Circus are fetching 15–20% above list. The median has jumped from $2.12M to $2.8M in 12 months.
Hillsborough: Old Money and New
- Median price: $5.14M
- Character: Rolling hills, estates, established wealth
- Average lot size: 1.5+ acres
Hillsborough remains the Peninsula's old-money enclave. Estates here are often 2–5 acres with multi-structure compounds. At $5.14M median, Hillsborough is pricier than Menlo Park but less astronomical than Atherton. It appeals to established executives and family offices seeking privacy and acreage without the hyper-profile of Atherton.
San Carlos: The Biotech Boom Town
- Median price: $2.19M average
- Key driver: Biotech jobs on Industrial Road
- Character: "Small town on the Peninsula" feel with suburban convenience
San Carlos is quietly becoming one of the most interesting markets in the county. The Alexandria Real Estate Equities campus on Industrial Road is a 2.5M+ square-foot biotech and lab complex, with plans to expand and add ~7,000 jobs. Engineers and scientists working in the South San Francisco biotech corridor (10 minutes away) are choosing San Carlos for its walkable downtown, schools, and reasonable prices relative to Menlo Park. As the biotech expansion accelerates, expect San Carlos to be a 2026–2028 growth story.
Redwood City: The Climate Best By Government Test
- Median price: $1.8M (down 1.9% YoY)
- Price per square foot: $1,270/sqft (up 5.2% YoY)
- Character: Tree-lined downtown, "Climate Best by Government Test," startup hub
Redwood City's downtown revival is real. The city's historic climate motto is more than marketing—the weather is genuinely mild year-round. Younger tech workers, especially those priced out of Menlo Park and San Carlos, are looking to Redwood City's downtown corridor. While the overall median is down 1.9%, price-per-square-foot is up 5.2%, indicating that higher-quality, newer homes in prime locations are commanding premiums.
San Mateo City: The Underdog
- Median price: $1.4M (down 8.1% YoY)
- Character: Diverse, urban, Caltrain-adjacent
- Trends: Emerging food and cultural scene
San Mateo city proper is cheaper than Redwood City, which seems counterintuitive given its proximity to the Caltrain and growing restaurant and retail scenes. The 8.1% YoY decline suggests modest buyer hesitation, but for commuters and urban-minded residents, San Mateo offers better walkability and cultural amenities than more suburban alternatives.
Foster City: The Connector
- Median price: $1.4M (up 0.4% YoY)
- Character: Planned community, lakes, family-friendly
- Trends: Flat to stable
Foster City's man-made lakes and planned-community design make it perennially attractive to families. The 0.4% YoY growth is practically flat, indicating steady-state demand rather than frenzy. It's a "buy and hold" market for long-term residents.
Millbrae: The Gateway
- Median price: $1.59M
- Character: Gateway to the Peninsula, BART/CalTrain access, diverse population
- Trends: Transit-oriented appreciation
Millbrae's proximity to both BART and CalTrain makes it valuable for commuters heading south to San Jose or north to San Francisco. The $1.59M median reflects this connectivity premium over San Mateo or Foster City.
Daly City: The Reality Check
- Median price: $1.1M (down 10.2% YoY)
- Character: Working-class, diverse, fog capital
- Trends: Price pressure but stable inventory
Daly City's 10.2% YoY decline is among the steepest on the Peninsula. The lower median price ($1.1M) reflects its position as a more affordable alternative to San Mateo or Redwood City, but price declines suggest buyer resistance in the sub-$1.2M segment.
South San Francisco: The Biotech Capital
- Median price: $1.2M typical
- Employers: Genentech, biotech corridor hub
- Character: Industrial, biotech innovation, future upside
South San Francisco is the biotech epicenter of the Bay Area. Genentech, founded in 1976 by Herbert Boyer and Stanley Cohen, employs 10,001–11,800+ employees and anchors the South San Francisco biotech hub. While residential prices are modest ($1.2M typical), the employment base is massive and growing. Scientists and biotech workers often buy in San Carlos, Redwood City, or Half Moon Bay rather than South San Francisco itself, but the jobs are the undeniable foundation of the Peninsula's future.
Half Moon Bay: Coastal Charm
- Median price: $1.35M–$1.7M range
- Character: Coastal town, pumpkins, agriculture
- Trends: Weekend-home and commuter appeal
Half Moon Bay offers ocean access, agricultural heritage, and a weekend-getaway vibe. The price range suggests bifurcation—more modest coastal homes at $1.35M, and premium oceanfront or acreage-heavy properties pushing $1.7M. For buyers seeking escape velocity from the high-pressure Peninsula but still want the region, Half Moon Bay delivers.
Pacifica: The Overlooked Gem
- Median price: $1.26M
- Character: Coastal, bohemian, accessible to SF via 280
- Trends: Emerging destination
Pacifica, 30 minutes from downtown San Francisco via Highway 280, offers coastal living at lower price points than Half Moon Bay. At $1.26M median, it's cheaper than San Mateo city, making it appealing for buyers priced out of the Peninsula proper but craving coastal access.
The Employment Drivers: Why Prices Are Where They Are
San Mateo County's housing market doesn't exist in a vacuum. Four major employment engines are reshaping demand:
Meta: 20,000+ Employees, Tech Equity Realizations
Meta Platforms operates its global headquarters in Menlo Park, employing 20,000+ people. In 2026, Meta cut 318 positions, a minor retrenchment after massive 2022–2023 layoffs. Despite the cuts, Meta's core workforce remains massive, and equity realizations from restricted stock units (RSUs) continue to fuel home purchases, especially in Menlo Park and Atherton. A senior Meta engineer with $2M+ in equity realization is a natural Menlo Park or Hillsborough buyer.
Market impact: Drives single-family home demand in the $2M–$5M range; creates the Menlo Park/Atherton wealth effect.
Genentech and the Biotech Corridor: 10,000+ Employees
Genentech, founded in 1976 as the world's first biotech company, remains the Bay Area's biotech flagship. Based in South San Francisco, Genentech employs over 10,000 people. The broader South San Francisco biotech corridor includes dozens of other life sciences companies, collectively employing tens of thousands.
The biotech industry is capital-intensive, employs highly educated scientists and engineers, and offers competitive salaries ($150K–$300K+). Biotech employees are buying in San Carlos, Redwood City, and Half Moon Bay—all areas within 10–20 minutes of South San Francisco.
Market impact: Stabilizes mid-market demand in the $1.5M–$2.5M range; makes San Carlos a growth story for 2026–2028.
YouTube and Google: Satellite Operations
YouTube's headquarters is in San Bruno, just south of San Mateo County proper. While YouTube/Google aren't as dominant on the Peninsula as in Mountain View or San Jose, their presence is material—especially for remote workers and satellite employees.
AI and Large Language Models: The New Wave
The rise of OpenAI, Google's AI initiatives, Perplexity, and other AI companies is reshaping the Bay Area talent market. Many AI researchers and engineers are choosing to live on the Peninsula (closer to San Francisco, better weather, better schools) while commuting to Mountain View or San Francisco offices 2–3 days per week. This emerging demand for "Peninsula proximity to AI jobs" is a 2026 trend worth watching.
Market Dynamics: The Data You Need
Inventory Crisis
Fewer than 1,000 homes for sale across San Mateo County for 740,000 residents. That's a 0.13% inventory-to-population ratio. For context, a healthy market has 5–6 months of inventory. San Mateo County has less than 2 months. This scarcity is the defining constraint on the market.
The Sale-to-List Spread
Single-family homes selling at 106.9% of list price vs. condos at 99.6% perfectly captures the demand disparity. Buyers are bidding up SFH; they're take-it-or-leave-it on condos.
Days on Market: The Patience Test
SFH at 9 median days vs. 12 days for condos might seem trivial, but it's not. A SFH is typically listed, showings start day 1, offers come by day 3–5, and homes close by day 9. A condo sits longer, suggesting more difficulty in matching buyer and property.
Price Per Square Foot: The True Indicator
At $1,070/sqft (SFH) in San Mateo County, you're paying roughly:
- Menlo Park: $1,400–$1,600/sqft
- Atherton: $2,200+/sqft (ultra-luxury)
- Redwood City: $1,270/sqft
- San Mateo city: $1,100/sqft
- Daly City: $900–$950/sqft
Price-per-square-foot variation is driven by school quality, commute time, and perceived prestige. Menlo Park's premium over San Mateo city is about 35%, reflective of the Meta wealth effect and better schools.
Assessment Roll Records
San Mateo County's Assessor's Office reports a $341.1B assessment roll, up 15 consecutive years. This record-high valuation reflects not just home prices but also new construction and property improvements. For homeowners, it means rising property taxes (via Proposition 13's reassessment on sale).
New Development: What's Coming
Two major projects are reshaping housing supply:
1700 El Camino Real (441 Units)
A mixed-use development on the iconic El Camino Real (the region's main commercial corridor) is adding 441 apartment units. These are primarily 1–2 bedroom rentals, not condos, so they won't directly impact the sales market but will affect the rental market and commuting patterns.
715 North San Mateo Drive (181 Apartments)
Another 181 rental apartments are coming to North San Mateo Drive. Again, these are rentals, not for-sale condos, but they increase housing density in the San Mateo area and may ease rental pressure.
Bottom line: San Mateo County is not adding single-family homes. New development is almost entirely rental apartments and mixed-use, which explains why single-family home inventory remains critically scarce.
Average Apartment Rent Trends
Average apartment rent: $3,604/month (up 4.53% YoY). For a 2-bed/1-bath apartment, expect $3,800–$4,500/month depending on location and amenities.
Trends Shaping 2026 and Beyond
1. The Single-Family Vs. Condo Divide Is Permanent
The divergence between SFH appreciation (up 7%) and condo depreciation (down 9%) reflects deeper changes in buyer preferences. Remote work and "work from anywhere" have made extra space—home offices, guest rooms, yards—valuable. Condos, especially smaller 1–2 bedroom units, are falling out of favor except among young singles and empty-nesters strictly seeking affordability.
Implication: If you own a condo, consider selling into the spring market (April–May 2026) before further decline. If you own a SFH, hold or rent out for the long term.
2. Luxury Market Outpacing Mid-Market
Luxury sales (homes above $2M) are up 39% YoY (2025), while mid-market (homes $1M–$2M) are flat to slightly down. This suggests that wealth concentration is driving ultra-high-end appreciation while middle-class buyers are squeezed.
Implication: The $1.93M median obscures a polarizing market. Homes at $2.5M–$5M are appreciating; homes at $1M–$1.5M are stagnating.
3. AI and Biotech Are the Future Demand Drivers
Meta is slowing hiring; Google AI is expanding; OpenAI talent is decentralizing to the Peninsula. By 2027–2028, expect biotech (Genentech, Alexandria Real Estate expansions) and AI (scattered across the Bay Area) to be the primary demand drivers for Peninsula housing. This favors San Carlos, Redwood City, and Half Moon Bay over Menlo Park/Atherton.
4. Caltrain Electrification + Remote Work = Commute Flexibility
Caltrain's electrification project (completion targeted for 2033) will reduce commute times from the Peninsula to San Francisco by ~10–15%. Combined with remote work normalcy (3–4 days in office), this makes South San Mateo County (San Mateo, Foster City, Pacifica) increasingly attractive for younger workers priced out of the Peninsula proper.
How Much Are You Really Paying in Commission?
This is where most sellers get blindsided. The standard real estate commission on the Peninsula is 5–6% of the sale price, split evenly between buyer's and seller's agents (2.5–3% each). But because sellers typically pay both sides, the effective cost is 5–6%.
Let's break down what that looks like for different price points across San Mateo County: