Place all ingredients in a large bowl and gently toss to combine. Cover and keep the salad refrigerated until ready to serve.
Options: For a more aromatic salad, use fragrant jasmine or basmati brown rice instead of regular brown rice. Use canned pinto beans instead of black beans if you prefer their somewhat milder taste. Use frozen corn kernels, thawed, instead of fresh. Use chopped green onion or parsley instead of cilantro if you don't care for the taste of that pungent herb.