NAICS 621111

Physician Practices in Mill Valley, CA

The 1 ZIP codes assigned to Mill Valley contained 35 Medical Practice establishments in 2023, of which 6 employed 10 or more people.

Establishments (2023)
35
1 ZIP codes
10 or more employees
6
Practical financing floor
Share of county
14%
Marin County
City population
13,799
2025 estimate

Figures cover the ZIP codes the U.S. Postal Service assigns to Mill Valley (94941). 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 Mill 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
1-42160.0%
5-9720.0%
10-19617.1%

How this market compares

Mill Valley against every other city in California on the same measure. City figures cover the ZIP codes assigned to the place rather than its municipal boundary, so they are compared as a share of the businesses in those same ZIP codes rather than per resident. Cities with fewer than 500 businesses in total are left unranked.

Typical2.74% of local businesses, against 2.85% statewide

About the same slice of the local business base as the industry holds statewide.

Vs state share
-4%
Share of local businesses
Rank by count
#170
of 373 cities
Rank by share
#128
of 297 ranked
Since 2020
-19%
Change in establishments

This compares how much of Mill Valley’s business base is physician practices, against the California figure. Base: 1,277 establishments across all industries in the same ZIP codes, 2023. It does not measure revenue, profitability or whether a market is worth entering.

Business size mix

Mill 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 establishmentsMill ValleyCaliforniaDifference
Under 5 employeesOwner-operated, often no management layer60.0%65.6%-5.6%
5 to 49 employeesThe range most individual buyers target37.1%27.4%+9.7%
10 or more employeesPractical floor for acquisition financing17.1%12.9%+4.3%

Nearest comparable markets

The closest places to Mill 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
Larkspur11n/a
Corte Madera19+30%
Sausalito9-56%
San Anselmo7-53%
San Rafael62-31%

The wider Marin County market

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

County establishments (2023)
255
Marin County
County employees
1,823
Mid-March employment
County annual payroll
$244M
All establishments
Full Medical Practice data for Marin 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 Mill 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.