Breadcrumb AMCP.org Resource Center Topics Formulary & Utilization Management AMCP submits letter to Illinois Senate Committee opposing House Bill 4146 which prohibits formulary changes during a plan year 5/8/18 AMCP submits letter to Illinois Senate Committee opposing House Bill 4146 which prohibits formulary changes during a plan year AMCP submits letter to Illinois Senate Committee opposing House Bill 4146 which prohibits formulary changes during a plan year.pdf Tags: Formulary & Utilization Management (60) Legislation & Regulation (8) Prior Authorization/Electronic Prior Authorization (ePA) (7) Specialty Tiers (5) Step Therapy (5)