Administrative divisions:

23 provinces (provincias, singular - provincia) and 1 autonomous city*; Buenos Aires, Catamarca, Chaco, Chubut, Ciudad Autonoma de Buenos Aires*, Cordoba, Corrientes, Entre Rios, Formosa, Jujuy, La Pampa, La Rioja, Mendoza, Misiones, Neuquen, Rio Negro, Salta, San Juan, San Luis, Santa Cruz, Santa Fe, Santiago del Estero, Tierra del Fuego - Antartida e Islas del Atlantico Sur (Tierra del Fuego - Antarctica and the South Atlantic Islands), Tucuman

note: the US does not recognize any claims to Antarctica

Definition:

This entry gives the numbers, designatory terms, and first-order administrative divisions as approved by the US Board on Geographic Names (BGN). Changes that have been reported but not yet acted on by the BGN are noted. Geographic names conform to spellings approved by the BGN with the exception of the omission of diacritical marks and special characters.

Source: CIA World Factbook