A generic drug is a medication that contains the same active ingredient, dosage, form, and strength as a brand-name drug but is sold under its chemical name once the brand-name drug's patent has expired. Generic drugs are approved by Health Canada and must meet the same standards for safety, efficacy, and quality as the original brand-name product. They are significantly less expensive — often 20% to 80% cheaper — because generic manufacturers do not bear the original research and development costs. Most Canadian insurance plans encourage or require the use of generics through formulary tier structures and generic substitution policies. Some plans implement mandatory generic substitution, meaning they will only reimburse the cost of the generic version when one is available, even if the pharmacist dispenses the brand-name drug.