A drug I'm interested in is listed twice. A formulary is a list of prescription drugs that a health plan has approved for use by doctors. Formularies may change at any time. This typically requires that your doctor contacts the plan either in writing or on the telephone and make the case for a non-formulary drug. This process can be time consuming and if successful, you will have to obtain authorization every 30 days for refills.
Health plans use formularies to control the cost of pharmaceutical health care.
There are various approaches as to how plans will implement control. Others will use guidelines and protocols to encourage physicians to prescribe according to a predetermined therapeutic strategy developed by the plans health professionals. And sometimes a formulary will include a mixture of these approaches. Formularies differ between health plans and you should compare availability of medications before making a choice of health plan. A generic drug is a copy of the original drug that is no longer protected by a US patent.