How long is breast milk good for in the refrigerator?

You can store breast milk in the refrigerator for up to 4 days at a temperature of 4°C or lower, provided it is stored in the back of the fridge, not the door. 

Milk can also be stored in the freezer for up to 12 months, but it is best used within 6 months to maintain its nutritional content, especially vitamin C. The longer it is stored, the more its nutritional benefits decrease.