Using recently developed econometric techniques to estimate quantile treatment effects (QTE) and experimental data, we examine the impact of Job Corps on earnings distribution. Our results indicate a great deal of heterogeneity in the effects of Job Corps. The QTEs show an increasing pattern along the earnings distribution, with much more pronounced differences at the upper quantiles for males, whites, and ages 20–24. Moreover, we find the QTEs to be very small at quantiles below the median for males, ages 16–17 and 18–19, and non-resident students. We propose strong economic conditions and skill hypotheses to explain the heterogeneity observed over the earnings distribution. Copyright © 2013 John Wiley & Sons, Ltd.