We typically drink from the water dispenser on the fridge door. It has a cartridge filter inside that is replaced every 90-120 days. Even then, one should take care to wipe out the filter enclosure with a disinfectant during every change. Some of the areas around the o-ring seals can grow mold/mildew.
Our new house has a water softening and filtration unit in the basement, which is kinda funny considering the quality of the water in that jurisdiction is very good. So I've gotta learn how to maintain and run it, as well as temporarily bypass it, if necessary.