Requirements for Italian-U.S. citizenship largely involve establishing an ancestral or marriage connection to Italy. For those who have family or business interests in the United States and Italy, being able to live and work freely in both countries is a means to maintaining their livelihood and family connections.
Requirements: First Generation Ancestry
In order to become a dual citizen, certain circumstances must apply. As stated by the Italian Consulate in New York, you may be considered a dual citizen according to jure sanguinis--meaning continuity of blood--if your father was an Italian citizen when you were born--and if you never renounced your right to Italian citizenship. Similarly, if your mother was an Italian citizen at the time of your birth, you were born after January 1, 1948, and you never renounced the right to Italian citizenship, then you can be considered a dual citizen.
Requirements: Second Generation Ancestry
The consulate also advises that you may be considered an Italian-U.S. citizen if, "your mother was born in the United States or a Country other than Italy, your maternal grandfather was an Italian citizen at the time of her birth, you were born after January 1, 1948, and neither you nor your mother ever renounced your right to Italian citizenship." Additionally, if "your father was born in the United States or a Country other than Italy, your paternal grandfather was an Italian citizen at the time of his birth, neither you nor your father ever renounced your right to the Italian citizenship," you may be considered a dual citizen.
Requirements: Third Generation Ancestry
Lastly, if "your paternal or maternal grandfather was born in the United States, your paternal great grandfather was an Italian citizen at the time of his birth, neither you nor your father nor your grandfather ever renounced your right to Italian citizenship," then you can be considered a dual citizen. However the Consulate states that, "a grandmother born before 01/01/1948 can claim Italian citizenship only from her father and can transfer it only to children born after 01/01/1948."
Various documents such as birth, death and naturalization certificates, marriage licenses, with an apostille and Italian passports are needed to show you meet dual citizenship criteria. These documents should be presented to the Consulate Authority in the jurisdiction in which you live. Further information can be obtained by visiting the Italian Consulate of New York or Philadelphia websites.
Non-Ancestry Dual Citizenship
According to the Italian Consulate General in Philadelphia, to gain Italian citizenship through marriage you must have maintained, "legal residence in Italy for a period of six months after the marriage or for three years after the marriage if residing abroad; [have a] valid marriage" and not have committed a crime, or violated national security. Note that a U.S. citizen who voluntarily applies for foreign citizenship unless she automatically have dual citizenship, as in the case of family ancestry.