In 2013 the state of California launched a cap-and-trade program with a groundbreaking protocol for improved forest management (IFM), providing a framework to monetize carbon sequestration in managed forests. Through in-depth interviews and document review, this research examines California's IFM program development as a case study in stakeholder-engaged ecosystem commodification. We consider how diverse, vested-interest actors contested rival program design options by using the familiar narratives of ecological modernization, green governmentality, and civic environmentalism. The results reveal the benefits and complexities of delegating methodological design to stakeholders who seek direct participation in the market, and highlight the challenges of balancing multiple program objectives, including environmental benefits, legitimacy and market reception, and landowner participation potential. This research provides a unique window into the complex process of forest-offset program design and offers broader lessons for ecosystem markets currently being designed and implemented globally.