NAICS 621111

Physician Practices in Fontana, CA

The 2 ZIP codes assigned to Fontana contained 37 Medical Practice establishments in 2023, of which 12 employed 10 or more people.

Establishments (2023)
37
2 ZIP codes
10 or more employees
12
Practical financing floor
Share of county
3%
San Bernardino County
City population
221,223
2025 estimate

Figures cover the ZIP codes the U.S. Postal Service assigns to Fontana (92335, 92336). 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 Fontana'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
1-42156.8%
5-938.1%
10-19821.6%
20-49410.8%

How this market compares

Fontana 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.

Thinly served1.03% of local businesses, against 2.85% statewide

A far smaller slice of the local business base than the statewide share. Either a genuine gap in provision or a market served from somewhere nearby. Worth checking the neighbouring places below before drawing a conclusion.

Vs state share
-64%
Share of local businesses
Rank by count
#164
of 373 cities
Rank by share
#260
of 297 ranked
Since 2020
-24%
Change in establishments

This compares how much of Fontana’s business base is physician practices, against the California figure. Base: 3,587 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

Fontana 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 establishmentsFontanaCaliforniaDifference
Under 5 employeesOwner-operated, often no management layer56.8%65.6%-8.9%
5 to 49 employeesThe range most individual buyers target40.5%27.4%+13.1%
10 or more employeesPractical floor for acquisition financing32.4%12.9%+19.6%

Nearest comparable markets

The closest places to Fontana 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
Rialto18-49%
Rancho Cucamonga180+18%
Jurupa Valley4-87%
Colton33+33%
Ontario47-70%

The wider San Bernardino County market

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

County establishments (2023)
1,202
San Bernardino County
County employees
11,149
Mid-March employment
County annual payroll
$1.2B
All establishments
Full Medical Practice data for San Bernardino 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 Fontana

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.