Sports franchises often value prior head coaching experience as they evaluate head coaching candidates. This paper empirically tests whether prior head coaching experience affects team performance in the National Football League. Accounting for individual coach effects and other relevant factors, I find that team performance is significantly worse beyond a given coach’s initial head coaching spell. These results hold for a variety of outcome measures. While coaches with the lowest levels of success in their initial head coaching spell have the most pronounced negative experience effects, significant negative effects are estimated for coaches at all levels of initial success. One explanation for these results is that human capital acquired through head coaching experience is to a large extent firm specific, so while learning does occur within a given head coaching job, it does not carry over to future coaching spells. This can lead to an erosion of any relative human capital advantage.