Managerial coaching is a process of feedback provision, behavioral modeling, and goal setting with subordinates to improve their performance and address their personal challenges. Despite the popularity of coaching as a management practice, the impact of coaching on objective measures of performance remains unclear. To this end, we tested a multilevel model linking managerial coaching frequency and skill to the sales goal attainment of 1,246 sales representatives in 136 teams within a pharmaceuticals organization over a year. Managers’ coaching skill, which was evaluated in the context of a training exercise, was directly related to the annual sales goal attainment of the sales representatives that they supervised. This effect was partially mediated by team‐level role clarity, as predicted by feedback intervention theory and goal setting theory. In addition, coaching skill had a cross‐level moderating effect on the relationship between coaching frequency and sales goal attainment; coaching frequency had a negative effect on goal attainment when coaching skill was low. We discuss the implications of this finding for coaching research and practice. Overall, our results demonstrate the clear theoretical and practical importance of effective managerial coaching by drawing on multisource and multilevel measurements with a predictive design.