Bring a large pot of salted water to a rolling boil. Add elbow macaroni and cook for 8-10 minutes, or until al dente. Drain and rinse under cold water. Set aside in a large mixing bowl.

Dice red bell pepper and slice green onions. Drain and rinse black beans and corn. Add all the vegetables to the bowl with the cooled pasta.

In a separate bowl, combine sour cream, mayonnaise, lime juice, taco seasoning, and garlic powder. Whisk until smooth and creamy.

Pour the dressing over the pasta and vegetable mixture. Gently toss everything together.

Cover the bowl and refrigerate the salad for at least one hour.

After chilling, stir the salad. Adjust seasoning if desired and serve cold.