Financial support is critical to sustain and improve the implementation of sustainability policies and initiatives. How capable are local governments to finance sustainability? Why are some governments more financially able than others to fund sustainability? How does stakeholder engagement improve financial capacity for sustainability? This study provides an explanation for sustainability funding that emphasizes political behaviors of institutional players in budgetary decision making. Using a database from U.S. cities, we find that an effective approach to enhance financial capacity for sustainability is to engage stakeholders to mobilize political support and technical expertise needed in resource allocation decisions for sustainability. Specific strategic actions to enhance financial capacity are recommended as part of a long-term and structured effort to sustain sustainability funding in local government.