We use a modified version of the stochastic frontier model to estimate oligopoly markups above the perfectly competitive frontier, separating out deterministic markups from purely stochastic markups. Using data from 42 US food processing industries between 1990 and 2010, empirical results indicate a widespread incidence of oligopoly power, with Lerner indexes averaging approximately 21%. Further, the estimated markups increase with industrial concentration but decrease with price elasticities and imports. Finally, the estimated Lerner indexes are in the range of previous food industry estimates using New Empirical Industrial Organization (NEIO) models.