Introduction: The objective of this study was to examine reimbursement trends for emergency provider professional services following the balance billing ban in California.Methods: We conducted a blinded web-based survey to collect claims data from emergency providers and billing companies. Members of the California Chapter of the American College of Emergency Physicians (California ACEP) reimbursement committee were invited to participate in the survey. We used a convenience sample of claims to determine payment rates before and after the balance billing ban.Results: We examined a total of 55,243 claims to determine the percentage of charges paid before and after the balance billing ban took effect on October 15, 2008. The overall reduction in percentage of charges paid was 13% in the first year and 19% in the second year following the balance billing ban. The average percentage of charges paid by health plans decreased from 91% to 86% from 2008 to 2010. Payments by risk-bearing organizations decreased from 72% to 46% of charges during the same time frame. Conclusion: Payment rates by subcontracted risk-bearing organizations for non-contracted emergency department professional services declined significantly following the balanced billing ban whereas payment rates by health plans remained relatively stable. [West J Emerg Med. 2014;15(4):518-522.]