Heat oven to 350 degrees F. Brown meat with peppers and onions in large skillet; drain. Return to skillet.
Stir in taco mix and water.
Add potatoes, corn and VELVEETA; mix well.
Spoon into 13x9-inch baking dish; cover with foil.
Bake 20 min.; stir. Bake, uncovered, 15 min. or until heated through.