As the role of US congressional parties in the legislative process has increased, so has the importance of understanding the institutions within these organizations. In this article, we examine the weekly caucus meetings held by Republican House leaders with their rank-and-file. We consider how members’ characteristics relate to their deci- sion to attend based on the collective and private benefits that caucus participation affords. Using interviews of members and staffers as well as members’ attendance records at these meetings from 2007 to 2013, we find, among other things, that members who vote less with their party or who have more seniority are less likely to attend while those in leadership positions or who are electorally vulnerable are more likely to do so. Together, these findings provide additional insights on the relationship between party leaders and their members and which members benefit from this central party-building activity.