Recent outbreaks of highly pathogenic avian influenza (HPAI) in Asia, Europe, and Africa have caused severe impacts on the broiler sector through production losses, trade restrictions and negative shocks to demand. This study develops a multimarket econometric model that is the basis of simulations to assess the spread and market implications of a potential HPAI outbreak in U.S. broiler industry. It takes into account market power that might exist within the livestock and meat sectors and endogenizes the optimal production condition on the model system. The results imply that the HPAI shocks affect prices at different marketing levels unequally and change the price margins along the supply chain with the existence of market power. The change in the price margin, although statistically significant, is quite small in absolute value.