Birdray

CSLB classification · Concrete/Masonry

C-51 Structural Steel Contractor

Erects structural steel.

1,489
Active licences
1,015
With workers' comp
68%
268
Renewing in 90 days
41
Lapsed or suspended
388
Exempt
9
New in 90 days

Coverages a producer should expect

  • ›Workers' comp
  • ›General liability with high limits
  • ›Umbrella
  • ›Crane and rigging

WCIRB classes usually assigned

  • 5040 Iron or steel erection, frame structures

Governing class depends on actual operations and payroll. Verify with the WCIRB classification search before quoting.

Carriers writing this class

Policies on file, statewide

  1. State Compensation Insurance Fund325
  2. Insurance Co. Of The West82
  3. Omaha National Casualty Co.79
  4. Zurich American Insurance Co.54
  5. Travelers Property Casualty Co. Of America43
  6. Pie Insurance Co.23
  7. Benchmark Insurance Co.21
  8. National Liability And Fire Insurance Co.15
  9. Hartford Casualty Insurance Co.14
  10. Carolina Casualty Insurance Co.14

C-51 workers' comp renewals by month, California

42
Sep
142
Oct
56
Nov
70
Dec
119
Jan
65
Feb
83
Mar
89
Apr
67
May
70
Jun
85
Jul
70
Aug
6
Sep

Counties with the most

  1. Los Angeles County312
  2. County154
  3. Orange County116
  4. San Diego County103
  5. San Bernardino County100
  6. Riverside County96
  7. Kern County49
  8. Alameda County48
  9. Sacramento County38
  10. Santa Clara County38
  11. San Francisco County31
  12. San Joaquin County30

Related classes in Concrete/Masonry

C-8 Concrete ContractorC-29 Masonry ContractorC-50 Reinforcing Steel ContractorD-06 Concrete-Related Services

Frequently asked

What does a C-51 licence allow a contractor to do?
Erects structural steel.
What insurance does a C-51 contractor need?
Workers' compensation is required by law once they have employees; the CSLB suspends a licence without it. Beyond that, producers usually place: Workers' comp; General liability with high limits; Umbrella; Crane and rigging.
How many C-51 contractors are there in California?
1,489 active licences hold the C-51 classification as of 2026-09-06; 1,015 (68%) have workers' comp on file and 388 are exempt.
When do C-51 workers' comp policies renew?
268 renew within 90 days. October is the peak month.
Which WCIRB class codes apply to C-51 work?
Most often 5040 (Iron or steel erection, frame structures). The WCIRB assigns the class from the actual operations and payroll, so verify per account in the WCIRB classification search.
Selling to C-51 contractors in California?
Birdray runs signal-timed outbound for one agency per territory: the companies behind these numbers, the person to email, and the renewal date, sent from your inbox. The database is free to search.
How the outbound worksSearch free

Sources: CSLB licence and workers' compensation records, California Secretary of State, OSHA, FMCSA, county permits. Aggregates only; no individual contractor appears on this page. "Active" means a CLEAR licence status. Renewal counts include policies on file with the CSLB expiring in the window. Refreshed weekly; this page as of 2026-09-06. Every field and its source →

C-51 Structural Steel Contractor: Insurance and WCIRB Classes | Birdray