What is the difference between USDA Prime and USDA Choice cut meats?

To earn the USDA Prime designation, beef must earn a specific quality grade at the time of slaughter. This grade is based on a combination of marbling (the amount of fat within the Ribeye) and age of the animal. Less than 5-6 percent of all beef produced in the United States earns this designation. Marbling adds flavor, and younger beef cattle produce the most tender meat, which is why the Prime grade is given to the younger cattle with the most abundant marbling. The Choice grade is given to meat that comes from younger cattle with moderate marbling. It is still very flavorful, tender and juicy.