Social support has been addressed as an important function for buffering and coping with stress. A number of mechanisms have been proposed over time with various empirical evidence. This study advances the theoretical understanding of the role of social support in the relation between role stress and role performance. In a moderated mediation test of 228 high school students taking their last year of college studies, the authors examine how social support interacts with the stress-performance relationship. Using objective performance measurements, our results showed that social support influences the level of experienced role stress (i.e., having a buffering effect) and at the same time interacts with the level of role stress on role performance (i.e., having a coping effect). Results underscore the importance of social support when examining stress coping mechanisms.