Breadcrumb Home Resource Center 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 (43) Legislation & Regulation (6) Prior Authorization/Electronic Prior Authorization (ePA) (5) Specialty Tiers (5) Step Therapy (5)