Elections in Puerto Rico are guaranteed by Article Six of the Constitution of Puerto Rico and the Electoral Code of Puerto Rico for the 21st Century Act. All processes are overseen and managed in whole by the Puerto Rico State Elections Commission; an autonomous agency of the executive branch of the government of Puerto Rico.
Three types of electoral processes can take place in Puerto Rico: general elections, referendum (aka, plebiscites), and special elections. General elections are held every four years on the first Tuesday after the first Monday of November, on the same day as the U.S. presidential election on Election Day. During these elections the people of Puerto Rico elect both local and central government candidates. These include the governor, resident commissioner, members of the legislative assembly, including senators and representatives, mayors, and municipal assembly representatives. Referendums can occur after a law has been enacted calling for a one. Special elections occur when an unexpected vacancy occurs on a post or for other similar matters.
Due to the political status of Puerto Rico, it being a U.S. territory instead of a U.S. state, U.S. citizens residing in Puerto Rico can not vote for their head of state, the President of the United States. Furthermore, the resident commissioner is a non-voting member of the U.S. House of Representatives, and Puerto Rico does not have any representation in the U.S. Senate. The resident commissioner is also the only member of the House of Representatives who serves a four-year term instead of a two-year term, and therefore Puerto Rico does not participate in the U.S. midterm elections.
Only American citizens (including Puerto Rican citizens) who meet all of the following requirements may vote: be a legal resident of Puerto Rico, be at least 18 years old by the date of the election, must have been qualified by the Puerto Rico State Commission on Elections before the election or on the very same day of the election after he presents himself to his nearest place of voting and shows proper documentation, and must have not been declared mentally incapacitated by a court.