National Coronavirus Commission Act of 2021 This bill temporarily establishes, in the legislative branch, the Commission on the Coronavirus Pandemic in the United States and sets out its powers, duties, and membership. The commission must investigate the facts and circumstances surrounding the COVID-19 (i.e., coronavirus disease 2019) pandemic. This investigation must include the preparedness for and response to the disease by federal, state, territorial, tribal, and local governments. The commission terminates 120 days after the submission of its final report. Additionally, the Government Accountability Office must monitor the implementation of any recommendations identified by the commission.