Founded in 1966 on Chula Vista's Third Avenue, CSS Insurance Services, LLC holds California License #0I81019 and maintains BBB A+ accreditation as a full-line commercial and personal insurance brokerage at 40 3rd Avenue. The agency's Certified WorkComp Advisor (CWCA) designation — conferred by the Institute of WorkComp Professionals — anchors a commercial division that underwrites workers' compensation, commercial auto, general liability, and surety bonds through over 50 carrier partners including Guard (Berkshire Hathaway) and Mercury, a contractor-focused portfolio that connects to the business-banking services at Enterprise Bank & Trust. The brokerage expanded from one office to seven locations across California while maintaining its Third Avenue Village headquarters directly across from the Chula Vista DMV. Restaurant insurance, contract and bid bonds, and Mexican auto policies round out the commercial book, while workers' compensation disputes requiring legal representation route to South Bay attorneys such as Debt Solution Law Group. The most complex accounts involve auditing multi-classification workers' compensation policies for experience-modification rate (EMR) errors, reclassifying payroll codes under WCIRB California's Uniform Statistical Reporting Plan, and recovering overcharges through NCCI audit-dispute procedures.