AbstractAre party switchers successful at furthering their careers? Most research on party switching focuses on the decision to switch and with which party to affiliate. Less attention is paid to the costs and benefits of switching parties. Moreover, previous research examining the electoral success of party switchers has often ignored how costs vary between the candidate selection process and the general election. This study addresses this gap in the literature by using original data on the careers of Mexican federal deputies to examine the costs and benefits of switching parties at the candidate selection stage and during general elections. The results suggest that party switchers are more successful at winning ballot access than nonswitchers but are less likely to win office. These results help explain why ambitious politicians would switch parties, given the known risks of changing party affiliation.