Implementing and growing a public health program that benefits society takes considerable time and effort. To ensure that positive outcomes are maintained over time, program managers and stakeholders should plan and implement activities to build sustainability capacity within their programs. We describe a 3-part sustainability planning process that programs can follow to build their sustainability capacity. First, program staff and stakeholders take the Program Sustainability Assessment Tool to measure their program's sustainability across 8 domains. Next, managers and stakeholders use results from the assessment to inform and prioritize sustainability action planning. Lastly, staff members implement the plan and keep track of progress toward their sustainability goals. Through this process, staff can more holistically address the internal and external challenges and pressures associated with sustaining a program. We include a case example of a chronic disease program that completed the Program Sustainability Assessment Tool and engaged in program sustainability planning.