How do legislative term limits affect representation? Proponents’ arguments that term limits would reduce partisan conflict and improve the quality of representation have received surprisingly little empirical scrutiny. We argue that term limits increase party polarization by changing legislators’ electoral and career incentives, in turn increasing the role of parties in legislative processes. Using panel data on roll call voting patterns from 1993 to 2016, we show that term limits produced systematically higher levels of polarization in state legislative voting patterns by increasing the ideological gap between Republicans’ and Democrats’ voting records. Consistent with our theoretical account, we further show that term limits had larger effects in more professional legislatures and increased contributions from party committees to legislative candidates. Contrary to the goals of their proponents, terms limits exacerbated the legislative consequences of contemporary partisanship and have implications for understanding how electoral and career incentives affect legislative outcomes.