The California Division of Workers' Compensation (DWC) released its annual report on the Independent Medical Review (IMR) program, managed by Maximus Federal Services.

IMRs resolve disputes over treatment denials or modifications from utilization review (UR). Understanding what products and services experience greater disputes is of value for workers’ comp programs, as well as understanding what services see higher rates of UR overturn.

The report utilizes data from 2023 to 2024. According to the report, a total of 199,651 IMR applications were received in 2024, a 14.07% increase from 2023. Approximately 141,621 final determination letters were issued, an increase of 8.29% when compared to 2023.

In 2024, pharmaceuticals made up 32.7% of IMR requests, marking a slight increase as these requests have been trending down since 2018. Among the pharmaceutical requests, opioids made up 23.91% of requests, followed by topical analgesics at 17.44%, and muscle relaxants at 16.31%.

Other top services that received IMR requests were rehabilitation services, making up 21.5% of requests, and diagnostic testing, making up 11.6% of requests.

The overturn rate for IMRs in 2024 was 12.7%, marking an increase from 10.2% in 2023. Evaluation and management services saw the highest overturn rate in 2024 at 23.1%.