Preferential trade agreements (PTAs) promise exclusive access for their members at the expense of excluded parties. But what does this exclusivity mean for firms in nonmember states if production networks are internationally organized? This paper analyzes the effect of PTA exclusion on firms embedded in the global supply chains, focusing on the case of China's exclusion from the Trans-Pacific Partnership (TPP). Drawing on a survey of Chinese firm managers during the TPP negotiations, we find that productive and downstream firms anticipated the exclusion and made adjustments accordingly, which led to a general sense of optimism toward the agreement. When presented with the prospect of an expanded TPP, however, firms are divided depending on how their own positions in the global supply chain complement or compete with the new member. These findings, validated with interviews in the field, suggest that the effects of PTA exclusion depend on the ability and need for firms to adjust. As a result, exclusion does not equate to an unalloyed loss for excluded firms.