Using generic drugs can save you and the plan money. A generic drug is a copy of an original brand-name drug that many companies now manufacture. Substituting generic for brand-name generally has no side effects. If your doctor prescribes a brand-name drug, ask if there’s a generic alternative because generic drugs are generally less expensive. In addition, if you choose a brand-name drug when a generic alternative is available, you pay the brand-name copay plus the difference in cost between the generic and brand-name drug.