I study the role of accelerators in the capability development of new ventures. Accelerators are cohort-based programs designed to support new ventures by providing resources such as mentoring, capital, and industry connections. Using eight cases of new ventures in an accelerator, I study how they develop capability for digital sustainability during the program. I find four stages of capability development: co-identification of needs, availing resources, learning, and origin of capability. Further, these capability outcomes depend on the founder’s expectations and perception, venture stage, team, priorities, external dependence, and engagement with the program.