National Infrastructure Investment Corporation Act of 20 21 This bill establishes the National Infrastructure Investment Corporation to finance infrastructure projects that are beyond the financing capabilities of states and cities, including to (1) prioritize projects in a fair and efficient manner, and (2) minimize financial costs to the federal government. The corporation must provide loans, loan guarantees, and bonds to eligible applicants for infrastructure projects in the United States. Every five years, the Government Accountability Office must evaluate the activities of the corporation from the previous five fiscal years and submit to Congress a report containing the results of the evaluation.