A formulary is a list of the medications covered by a plan. Formularies vary in size based on the plan you select. Lower-priced plans may offer fewer prescription drugs on its formulary. You may find that plans that have a higher premium may have a broader formulary, with a wider selection of brand-name and generic medications. You can find out which specific medications are covered by looking at a plan’s drug list during the Open Enrollment period. You can usually review enrollment materials like the formulary online, call Customer Service, or request a formulary be mailed to you.