Nausea and vomiting are common symptoms in cancer patients undergoing chemotherapy and radiation therapy. In some cases, failure to control nausea and vomiting in cancer patients may result in reduced nutritional status and quality of life, and may prompt the refusal of continuing chemotherapeutic and radiation therapy cycles. The benefits and harms of antiemetic regimens including a 5-hydroxytryptamine-3 (5-HT3) antagonist and a corticosteroid, with and without aprepitant, have been researched in many clinical studies. However, these antiemetic regimens need to be evaluated in the context of the specific programmatic interests of Centers for Medicare & Medicaid Services in terms of all-oral regimens compared with one another, all-oral regimens compared to all-injectable regimens, and mixed oral compared with injectable regimens. Additionally, the applicability of the evidence to patients age 65 and older needs to be determined.