You really would not want them to completely "drop" the milk, as it gives them nutrients and calcium. Most toddlers are still encouraged to drink milk throughout the toddler years (and beyond); usually up to 20 oz per day. However, the method (i.e. bottle vs sippy/cup) often switches as do the times (some LOs get milk just with meals, some continue morning and night). They can of course get calcium from foods as well, but some milk intake is often still encouraged.