A bill to establish the National Commission on Terrorist Attacks Upon the United States, and for other purposes.

Establishes a National Commission on Terrorist Attacks Upon the United States, which shall: (1) examine and report on the facts and causes relating to the terrorist attacks against the United States of September 11, 2001; (2) ascertain, evaluate and report on the evidence developed by all relevant Government agencies regarding the facts and circumstances surrounding the attacks; and (3) identify and review the lessons learned regarding the structure and makeup of the Federal Government and, if necessary, of State and local governments and of nongovernmental organizations, with regards to detecting, preventing and responding to such terrorist attacks.(Sec. 5) Empowers the Commission to hold hearings, collect relevant materials, and subpoena witnesses.Applies Federal law to make failure to obey a subpoena by the Commission a misdemeanor crime against Congress punishable by a fine and imprisonment.Permits Commission meetings or portions to be closed to the public for national security reasons. Directs executive departments, agencies and other entities to provide information to the Commission upon request as authorized by law.(Sec. 8) Authorizes Executive departments and agencies to issue security clearances to members of the Commission, except that no individual on the Commission shall receive access to classified information who would not otherwise qualify for such a security clearance.(Sec. 9) Directs the Commission to issue a report to the President and Congress within six months after the first meeting, and a second report a year later, with recommendations for corrective measures.(Sec. 10) Authorizes appropriations.