NAICS 621111

Physician Practices in Portola Valley, CA

The 1 ZIP codes assigned to Portola Valley contained 9 Medical Practice establishments in 2023, of which 3 employed 10 or more people.

Establishments (2023)
9
1 ZIP codes
10 or more employees
3
Practical financing floor
Share of county
2%
San Mateo County
City population
4,292
2025 estimate

Figures cover the ZIP codes the U.S. Postal Service assigns to Portola Valley (94028). ZIP areas are not municipal boundaries: they can extend beyond city limits and are shared between neighbouring places. This is a count of establishments in Portola Valley's ZIP codes, not a count of businesses inside its city limits.

Establishments by size

Employee-count distribution. For most buyers the businesses worth pursuing sit in the 5 to 49 range: large enough to have a manager and real systems, small enough to be owner-operated.

EmployeesEstablishmentsShareDistribution
1-4444.4%
10-19333.3%

Business size mix

Portola Valley is more consolidated than California as a whole: fewer micro-operators and a larger share of businesses with real headcount. Fewer targets, but the ones that exist are more likely to be financeable.

Share of establishmentsPortola ValleyCaliforniaDifference
Under 5 employeesOwner-operated, often no management layer44.4%65.6%-21.2%
5 to 49 employeesThe range most individual buyers target33.3%27.4%+5.9%
10 or more employeesPractical floor for acquisition financing33.3%12.9%+20.5%

Nearest comparable markets

The closest places to Portola Valley that also have Medical Practice establishments on record. Useful for spotting a gap next door, or realising the market you are looking at is already served from the town over.

MarketEstablishmentsVs state share
Palo Alto91-17%
Atherton8n/a
Los Altos41+6%
Mountain View93+10%
Menlo Park46-8%

The wider San Mateo County market

Employment and payroll are reported at county level only, so the figures below describe the county Portola Valley sits in.

County establishments (2023)
405
San Mateo County
County employees
4,466
Mid-March employment
County annual payroll
$610M
All establishments
Full Medical Practice data for San Mateo County

What acquirers look at

California’s corporate practice of medicine doctrine restricts lay ownership, so deals are structured as MSO arrangements. Not a first acquisition for an unlicensed buyer.

Other industries in Portola Valley

Nearby cities

Sources

  1. U.S. Census Bureau, 2023 ZIP Code Business Patterns. Establishment counts and size distribution by ZIP code and NAICS, aggregated over the ZIP codes assigned to each city. Retrieved 2026-09-08.
  2. U.S. Census Bureau, 2023 County Business Patterns. Establishment counts, employment and annual payroll by NAICS. Retrieved 2026-09-08.
  3. U.S. Bureau of Labor Statistics, Quarterly Census of Employment and Wages (2026Q1). Quarterly establishment counts and employment for employers covered by unemployment insurance. Retrieved 2026-09-08.