Plumbing contractors in San Mateo by the numbers
San Mateo is home to 53 licensed plumbing contractors (C-36, CSLB September 2026), about 8% of the 634 contractor licenses based here.
Nearby in San Mateo County: Daly City (55), South San Francisco (51), Redwood City (47), San Bruno (43).
40% of San Mateo's C-36 licensees hold more than one classification — most often B General Building Contractor (28%), C-10 Electrical Contractor (13%). Extra classifications can change how carriers rate your general liability and workers' comp, so list every license class when you quote.
Business structure: 49% sole owners, 43% corporations, 8% LLCs; median time licensed 17.3 years.
What carriers look at
For plumbers, underwriters focus first on: mold claims that follow slow leaks; and sewer backup and drain-cleaning work. See the full coverage guide for plumbing contractors for limits, endorsements and workers' comp rules.
Get a quote
Asena Capital Insurance Services compares multiple markets for San Mateo contractors and requests additional insured endorsements for you when a contract calls for them. Call (858) 925-9555 or request a quote — only your name, phone and email are required. CA License #6008596.
Frequently asked questions
How many licensed plumbing contractors are in San Mateo?
53 active C-36 licenses have a business address in San Mateo (CSLB, September 2026); 43% carry workers' comp and 55% are filed exempt.
Do C-36 plumbers need workers' comp?
Yes if you have employees. With no employees you can currently file an exemption; beginning January 1, 2028, CSLB will require workers' comp for all active licenses under SB 1455, except joint ventures.