This study investigates how green purchasing in local governments varies as a function of the organization's internal commitment, operationalized by the stage of institutionalization of green public procurement (GPP), and external pressures from various stakeholder groups. GPP, a value‐based innovation justified on the grounds of intergenerational equity, is an important tool governments can use to mitigate the adverse effects of climate change. Survey data from 210 U.S. local governments reveal that while both external and internal factors are strong predictors of buying green, internal commitment matters relatively more. We also find that earlier stages of GPP institutionalization are more conducive to external influence, albeit the effect differs among stakeholders. Local governments tend to be more likely to buy green when nudged by nonprofits and interest groups, and less so when offered financial incentives by the federal government.