Abstract: Large-scale AI upskilling initiatives represent a critical organizational response to generative AI adoption across knowledge-intensive sectors. This article examines enterprise strategies for workforce AI capability development, analyzing Citigroup's 175,000-employee prompt engineering training program alongside parallel initiatives at JPMorgan, Bank of America, and Wells Fargo. Drawing on evidence from organizational learning, change management, and human-capital development research, the analysis identifies key success factors including adaptive learning design, continuous upskilling architectures, psychological safety cultivation, and integration with broader digital transformation efforts. The article argues that sustainable competitive advantage from AI derives not from technology deployment alone but from systematic human capability building that positions AI as augmentation rather than replacement. Organizational responses span mandatory foundational training, role-specific advanced modules, leadership development, and cultural interventions addressing workforce concerns about technological displacement. The findings suggest that effective AI workforce transformation requires coordinated attention to skills development, organizational culture, change communication, and long-term learning infrastructure.