Using the 1990, 1994 and 1998 Congressional mid-term elections, this study looks at whether the type of primary system in a person's state has an effect on whether or not that person will vote in the general election. The five types of primary systems (closed, semi-closed, semiopen, open and blanket) are explained as well as traditional factors for likelihood of voting. It is hypothesized that the more closed the primary system, the less likely a person is to vote. Data analysis shows that when significant, living in an open primary state does significantly increase the likelihood that a person will vote. However, primary type was significant in only six of the nine models studied here.