A formulary is a continuously changing list of preferred drugs, both generic and brand name, that are covered by a specific health plan. If a drug is not on the list, the patient will pay more, up to the full cost of the drug. The purpose of a health plans' formulary is for a person to get the least expensive medications that are adequately effective for treating a health condition. Some health plans' have different categories of medications called tiers; your co-payment, the shared cost of a prescription, is determined by the tier of your medication. Tier 1 includes generic medications and has the lowest co-payment. Tier 2 includes preferred brand name medications and has a higher co-payent than tier 1. Tier 3 includes non-preferred brand
