Before 1967, the Constitution left serious gaps. It was unclear whether a Vice President who took over became President, there was no way to fill a vice presidential vacancy, which happened sixteen times, and nothing said what to do if a President was alive but disabled, as Woodrow Wilson was after his 1919 stroke and Dwight Eisenhower was after his 1955 heart attack. The assassination of John Kennedy in 1963, which left the nation without a Vice President for more than a year, prompted Congress to act.
This guide explains each section of the amendment, how it has been applied, and the questions that remain.
Section 4 was designed for physical or mental incapacity, not for policy disagreements or misconduct, which are addressed by elections and impeachment. Scholars debate how inability should be judged, whether acting Cabinet secretaries may participate, and how the White House medical staff should be involved. Supporters say the amendment is a crucial safeguard for continuity, while some warn that Section 4 could be misused in a political crisis.
A President who expects to be unable to serve, for example during surgery under anesthesia, can send written declarations to the President pro tempore and the Speaker, making the Vice President acting President until the President sends a second declaration resuming power. Presidents have used this procedure for short medical procedures in 1985, 2002, 2007, and 2021, each lasting a few hours or less. It was not used after the 1981 assassination attempt on Ronald Reagan, a decision later criticized.
Section 1 states that in case of the removal of the President from office or of his death or resignation, the Vice President shall become President. It wrote into the Constitution the precedent John Tyler set in 1841. It was applied when Gerald Ford became President after Richard Nixon resigned on August 9, 1974.
If the Vice President and a majority of the Cabinet, or of another body Congress creates, declare in writing that the President cannot discharge the powers and duties of the office, the Vice President immediately becomes acting President. If the President contests the declaration, Congress must decide within 21 days, and the Vice President remains acting President only if two thirds of both chambers agree. The alternative body has never been created, and Section 4 has never been invoked, though it was discussed in 2017 and after January 6, 2021, when the House passed a resolution urging its use.
When the vice presidency is vacant, the President nominates a Vice President, who takes office after confirmation by a majority of both the House and the Senate, the only appointment in which the House votes. Ford was confirmed in December 1973 after Spiro Agnew resigned, and Nelson Rockefeller in December 1974 after Ford became President, leaving the country for a time with a President and Vice President neither of whom had been elected to their offices.
Senator Birch Bayh of Indiana led the effort in Congress, drawing on proposals from the American Bar Association. Congress proposed the amendment on July 6, 1965, and Nevada provided the decisive ratification on February 10, 1967. The amendment aimed to ensure that the nation would always have a functioning President and Vice President.
See the full line of succession in presidential succession explained, learn about the office next in line in the vice presidency explained, or compare removal for misconduct in impeachment explained.