A meat thermometer inserted into the center of the best meatloaf will read 155° F when it is time to pull it out of the oven. Take it out and allow it to rest for 10 to 15 minutes. The rest time will allow the meat to reach the USDA recommended 160° as it continues to cook from residual heat. This rest period also allows for the redistribution of juices and for the meatloaf to set up more firmly.