Numerous feed additives are utilized in feedlot diets for various purposes including growth, efficiency, carcass merit, and for prevention and treatment of disease. This article is to review the most common feed additives utilized in feedlot cattle in North America as well as their indications and restrictions. The Veterinary Feed Directive will require veterinarians to understand these principles for feed-grade antibiotics for purposes of writing prescriptions in coordination with colleague nutritionists.