I draw together theories of partisan polarization and motivated reasoning, which suggest that partisanship shapes information processing, and theories of accountability, which argue voters hold elected officials accountable through promise fulfillment. Here, I ask how partisanship influences voter understanding of promise fulfillment and accountability and if voters assess promises through a partisan lens. Two original survey experiments test how respondents react to promise fulfillment on the issues of immigration and human trafficking. I demonstrate that co-partisans differentiate between kept and broken promises, but out-partisans do not. Despite partisan differences, respondents evaluate promise-keeping when asked about accountability but not when asked about approval. Thus, even when voters recognize broken promises, accountability is influenced by partisanship. Immigration, a more polarized issue, is more likely to prime a partisan response than human trafficking, a less polarized issue. Future work must account for partisanship in accountability and what this means for our understanding of fundamental democratic principles.