Program Information JLK Rosenberger is a full service accounting, tax, and business advisory firm with offices in Los Angeles, Dallas and Orange County. We are the 4th largest insurance practice in California and the 18th largest in the country as recognized by AM Best. Our clients attest they have chosen JLK Rosenberger for the following reasons: specialized industry knowledge, more attentive service, immediate access to decision makers, a better understanding of their organization and mission, and lower staff turnover.