Human-centered AI (HCAI) envisions artificial intelligence systems that augment human capabilities, support social goals, and operate within structures that uphold accountability and public trust. As AI becomes increasingly embedded in high-stakes domains, realizing this vision requires more than high-level ethical principles—it demands concrete tools and institutional structures that ensure responsible development and deployment. This chapter examines how standards and governance frameworks can serve as foundational mechanisms for operationalizing HCAI. It defines technical and ethical standards, reviews major international and regional standardization efforts, and distinguishes their role from governance frameworks that enable implementation, oversight, and continuous adaptation. Despite the proliferation of AI policy initiatives, serious implementation challenges remain. This chapter identifies three persistent barriers—value conflicts in application, institutional and regulatory fragmentation, and the accelerating pace of technological change—that undermine progress. Through two case studies—an AI recruitment system and a predictive policing program—this chapter illustrates how the absence or failure of context-sensitive standards and governance structures can result in discriminatory, opaque, and unaccountable outcomes. It concludes by underscoring the need for sector-specific standardization, institutionalized oversight, and inclusive, adaptive governance to bring the principles of HCAI into practice.