The answer depends on the time frame, the neighborhood, and whether you're looking at condos or detached houses. Anyone giving you a universal one-word answer is probably skipping the interesting part.
Use comparable periods
Compare the same property category year over year and quarter over quarter. A city's median can change because more large homes sold, even if individual home values did not increase at the same pace.
What the MLS page shows
MLSListings' September 2026 San Mateo snapshot reports a roughly $2.175 million median for single-family homes and a decline of about 9.4% over the preceding three months. That is a movement in reported median sale price, not proof that every home lost 9.4% of its value.
What buyers and sellers should do
Track closed comparables, inventory, pending competition, concessions, and condition adjustments. One neighborhood's market can move differently from the citywide trend.
What this means for you
Every San Mateo property has its own competition, condition, and financial considerations. The right decision comes from evaluating real numbers and your priorities, not assuming that one headline works for everyone.
I’m Olivia McNally. For more than 13 years, I’ve helped Bay Area clients navigate important real estate decisions with thoughtful, candid guidance. What would you most like to understand about your San Mateo property or next move? Let's talk through the options.
An Important Distinction About Asking Prices
In parts of the Peninsula, the strategic list price may be below the anticipated market value to encourage competitive offers; elsewhere pricing closer to expected value is more appropriate. A sale above asking does not automatically mean prices are appreciating by the same percentage. Compare closed sales, not just the list-to-sale spread.
Olivia's Peninsula-Level Perspective
A reported 2.5% year-over-year change in the September 2026 detached median is not equivalent to the change in value of every individual house. Property mix, condition, neighborhood and sample size affect the statistic. Evaluate matched comparable homes.
Not all medians represent appreciation
If more large remodeled houses close one month, the median can rise even when the price of an otherwise identical home doesn't. I look for matched comparables and confirm the period and property type. The home-value article explains how individual house condition and location can outweigh a citywide chart.
What I'd want you to understand before deciding
First, use comparable houses rather than compare a condo median with a detached-home median. Second, look at both year-over-year and recent sequential movements, noting the sale counts. Third, consider what was available for buyers to choose from when those sales were negotiated. Changes in mix, renovations and one unusually expensive transaction can affect the figures. If you're selling, the pricing decision should rest on your home's specific competition, not a percentage pulled from a citywide headline.