Revise workers' compensation laws relating to competitive markets

This bill updates Montana's workers' compensation laws to strengthen oversight of competitive markets by requiring the Insurance Commissioner to annually measure market concentration using the Herfindahl-Hirschman index. It directly affects workers' compensation insurers, employers, and the state fund by establishing clear criteria for determining whether a competitive market exists and mandating corrective actions if competition is found lacking. Key provisions include a presumption that a competitive market exists unless proven otherwise, specific factors the commissioner must evaluate such as insurer numbers and market shares, and required steps like promoting new insurers and limiting large mergers if the market is deemed noncompetitive. The bill also sets a threshold where an index score over 1,800 triggers a presumption of noncompetition and requires a public hearing to confirm the finding.