Yes, at least every six months, that's at a minimum. However, if your water is less than perfect, you may have to change it more often. Most filters come with a warning light to indicate if it needs changing. Without that, you should check it about every three months to see if it's OK. It's not hard to see if there's a build-up on the filter, and if you see anything at all, change. At least every 6 months. Inside of most refrigerator water filters is a activated carbon block wrapped in a type of paper skin. Actived carbon is excellent at taking out water impurities and chlorine. The paper skin acts as a prefilter and will plug up with dirt and sediment. Pending on your incomming water quality you should change your filter per the manufactures spec's of every 6 months.