Cooked ground beef can be refrozen according to the USDA. Raw ground beef that has been thawed in cold water or the microwave should not be refrozen.
A safe way to thaw ground beef is in the refrigerator. This helps to prevent the growth of bacteria. Once thawed, the ground beef should be cooked or refrozen within one to two days. Ground beef should never remain at room temperature more than 2 hours.
It is dangerous to consume raw or undercooked beef, as it may contain harmful bacteria. Using a meat thermometer to make sure that beef is thoroughly cooked to 160 degrees ensures it is safe to eat.