Order of U.S. Presidential Succession
The Vice President
Speaker of the House
President pro tempore of the Senate
Secretary of State
Secretary of the Treasury
Secretary of Defense
Attorney General
Secretary of the Interior
Secretary of Agriculture
Secretary of Commerce
Secretary of Labor
Secretary of Health and Human Services
Secretary of Housing and Urban Development
Secretary of Transportation
Secretary of Energy
Secretary of Education
Secretary of Veterans Affairs
NOTE: An official cannot succeed to the Presidency unless that person meets the Constitutional requirements.
Qualifications for the office of President: No person except a natural born citizen, or a citizen of the United States, at the time of the adoption of the Constitution, shall be eligible to the office of President; neither shall any person be eligible to that office who shall not have attained to the age of thirty-five years, and been fourteen years a resident within the United States.
(From Article II, Section I of the U.S. Constitution)