The United States Constitution currently has 27 amendments.
The first ten amendments, known collectively as the Bill of Rights, were ratified in 1791. They protect rights including freedom of speech, religious exercise, due process, and protection against unreasonable searches. The Constitution’s amendment process is deliberately demanding, requiring proposal and ratification through specific federal and state procedures.
The most recent amendment, the Twenty-seventh Amendment, was ratified in 1992. It concerns congressional pay and says that changes to legislators’ compensation cannot take effect until an election for the House of Representatives has occurred.
The number 27 does not mean that only 27 amendments have ever been proposed. Thousands of amendments have been introduced in Congress, but only a small number completed the ratification process. Two proposals from the original Bill of Rights were not ratified at the time; one eventually became the Twenty-seventh Amendment.