N urse practitioners (NPs) have been providing diagnosis and treatment, within their scope of practice, for work related injury and illness in California for more than 20 years. However, this NP care has been mostly "invisible" to policy makers because NPs are not specifically listed as treating providers in the California Labor Code. Additionally, since 1994 there have been several regulatory changes and administrative decisions that have provided greater visibility of NP practice in the California workers' compensation (WC) system, but have resulted in a narrow interpretation of the NP role. The interpretation is that NPs can provide care and get reimbursed in the WC system, but are limited in outlining or modifying a treatment plan, certifying disability, or signing a "Doctor's First Report of Injury" (DFR). These changes have caused confusion among insurance carriers, employers, attorneys, physicians, and occupational health nurses about the NP role in the WC system in California. This confusion comes at a time when there are limited data about NP outcomes in the WC system, and a