Voluntary Sustainability Standards have become a popular private governance framework for more sustainable agri-food value chains. Yet, amid increasing concerns over the decoupling of standards and practices, it is still unclear to what extent agricultural standard requirements are implemented on the ground, and what may account for such differential implementation. This study employs a novel dataset of 659 Honduran coffee producers to examine this puzzle, focusing on the most widely used standards in the coffee sector (Common Code for the Coffee Community, Fairtrade, Fairtrade/organic, UTZ Certified, and Rainforest Alliance). It first presents results on implementation and behavioral change, based on matched groups of certified and non-certified farmers, for eight representative social and environmental sustainability practices. Analyzing determinants of implementation success, it finds that the stringency of rules – if they are known by farmers – and the level of farm-gate prices are significantly correlated with farmers’ performance and lower levels of decoupling across a majority of indicators. These results speak to the importance of supporting small-scale actors’ awareness of and financial capacity to comply with proposed sustainability rules.