Prepare pasta according to package instructions, rinse and set aside.
Meanwhile, brown ground beef with onion over medium-high heat. Drain any excess drippings.
Add chili powder, soup, water, chili, and beans. Stir. Salt and pepper to taste.
Fold in macaroni.
Turn heat down to low. Top with slices of American cheese, place lid on skillet until cheese melts. Serve.
