According to the U.S. Department of Agriculture, corned beef can be frozen. The USDA recommends that corned beef be frozen for no more than two or three months.
If corned beef is left over after a meal, the USDA urges that the meat be refrigerated within two hours of cooking. Corned beef can be stored in the refrigerator for three or four days. The USDA notes that cold corned beef is easier to cut into uniform slices, and it is easy to reheat and serve. The corned beef can be sliced or cut into pieces for faster cooling, and it should be stored in shallow containers. Leftover corned beef should be heated to a temperature of 165 degrees Fahrenheit.
According to About.com, uncooked vacuum-sealed corned beef in its original packaging can be stored in the freezer for a month before it is cooked. While frozen uncooked corned beef does not need to be thawed before it goes into a pot of simmering water to cook, Skylark Meats recommends thawing the meat in a refrigerator or a water bath before cooking it.