This paper models a frictional labor market where employers endogenously discriminate against the long term unemployed. The estimated model replicates recent experimental evidence which documents that interview invitations for observationally equivalent workers fall sharply as unemployment duration progresses. We use the model to quantitatively assess the consequences of such employer behavior for job finding rates and long term unemployment and find only modest effects given the large decline in callbacks. Interviews lost to duration impact individual job finding rates solely if they would have led to jobs. We show that such instances are rare when firms discriminate in anticipation of an ultimately unsuccessful application. Discrim- ination in callbacks is thus largely a response to dynamic selection, with limited con- sequences for structural duration dependence and long term unemployment.