National Infrastructure Development Bank Act of 2021 This bill establishes the National Infrastructure Development Bank as a government corporation to finance energy, environmental (e.g., drinking water or waste facilities), telecommunications, and transportation infrastructure projects. The bill establishes the National Infrastructure Development Bank Board, which must oversee the infrastructure projects. The board may make loans and loan guarantees to assist in financing infrastructure projects. Further, the board must establish an executive committee, a risk management committee, an audit committee, and a compliance office. To be eligible for financial assistance from the bank, an infrastructure project (1) must have a public benefit, as determined by the board; and (2) may not have a sole use or purpose that is private. An infrastructure project must use iron, steel, and manufactured products that are made in the United States. The bill also establishes accounting and reporting requirements. In particular, the Government Accountability Office must, within five years of this bill's enactment, submit a report to Congress evaluating the bank's activities.