Any citizen 18 years of age or older may register to vote and enroll in a party at the Registrars of Voters Office. All voters must be 18 years of age on election day in order to vote. Voters turning 18 by election day may also vote in a primary for that election. 

In the State of Connecticut, if you are registered as Unaffiliated, you cannot vote in a party primary election. In order to vote, you must be registered in the party that is holding the primary.