MRE (Meal Ready to Eat) shelf life is a little bit tricky. Like most shelf stable, long term food storage items, there are important things to know in order to store them properly. The most important concept to understand with MRE shelf life is:
According to Temperature What that means is the cooler the storage temperature, the longer the shelf life and inversely, the warmer the storage temperature the shorter the shelf life. It is quite possible that an MRE that is sent to the dessert in Iraq where the temperature is 120 degrees Fahrenheit will only stay fresh for a period of a few months. Whereas an MRE that is stored in a cool basement that is 65 degrees year round will store for a decade or so.
The Natick Army laboratory has done quite a bit of research on the shelf life of MREs and they have come up with this very handy chart to help you see how the long the MREs will store for based on temperature.
Here is the chart: 
As you can see it is important in storing your MREs to maintain a constant temperature. That will help MREs store for longer. We've had people tell us that they'll eat MREs that have been in their packs for 10+ years.
Obviously, eat any MRE that has expired at your own risk. Many of the MRE foods will lose their flavor, nutritional value, and coloring the longer they store. For example, apple sauce will turn from a soft yellow color to a darker brown. To avoid this problem, you'll just need to be on top of your MRE supply and make sure you don't have anything in your emergency supplies that is too old.
