Preheat the oven to 375°F.
Heat a large skillet over medium-high heat, add the beef, and cook until no pink remains. Drain fat. Add the taco seasoning and cook 2 minutes more.
Add the beans, corn, soup, ½ cup cheese, milk, sour cream, onion powder and pepper to the beef and stir well to combine.
Grease a 9x13-inch casserole dish and add half of the tater tots. Spread the beef mixture over top.
Top with the remaining tater tots and sprinkle with remaining cheese.
Bake uncovered until browned and bubbly, 20-25 minutes.
