2022
Presidential Succession Act
From Wiki:
The United States Presidential Succession Act is a federal statute establishing the presidential line of succession.
Article II, Section 1, Clause 6 of the United States Constitution authorizes Congress to enact such a statute:
Congress may by Law provide for the Case of Removal, Death, Resignation or Inability, both of the President and Vice President, declaring what Officer shall then act as President, and such Officer shall act accordingly, until the Disability be removed, or a President shall be elected.
Congress has enacted a Presidential Succession Act on three occasions: 1792 (1 Stat. 239), 1886 (24 Stat. 1), and 1947 (61 Stat. 380). The 1947 Act was last revised in 2006.
https://en.wikipedia.org/wiki/Presidential_Succession_Act
More from EveryCRSReport.com :
The Presidential Succession Act of 1947
In 1945, Vice President Harry S Truman succeeded as President on the death of Franklin D. Roosevelt.
Later that year, he proposed that Congress revise the order of succession, placing the Speaker of the House and the President Pro Tempore of the Senate in line behind the Vice President and ahead of the cabinet.
The incumbent would serve until a special election, scheduled for the next intervening congressional election, filled the presidency and vice presidency for the balance of the term.
Truman argued that it was more appropriate to have popularly elected officials first in line to succeed, rather than appointed cabinet officers.
A bill incorporating the President's proposal, minus the special election provision, passed the House in 1945, but no action was taken in the Senate during the balance of the 79th Congress.
https://www.everycrsreport.com/reports/RL31761.html