The National Health Mission (NHM) was launched in India in 2005 to improve population health by restructuring the health system and enhancing primary care. After nearly 20 years, it is essential to review its impact on the health system. This scoping review is the first of its kind which aimed to review and synthesize research on the effects of the NHM on human resources for health and governance, and its overall impact on the health system. We identified 46 research articles, 19 (41%) on human resources for health, 17 (37%) on governance, and 14 (30%) studying the overall impact. Most of the research on human resources was focused on the ASHA program and RKS and VHSNC dominated governance research. Maternal and child health studies dominated the health system impact literature. Outcomes show a partial achievement of the NHM's goals. Health workforce supplementation has improved access to healthcare in rural areas but remains inadequate to rising demand. Similarly, decentralization mechanisms have improved accountability, however, more community empowerment is needed. Healthcare demand has staggered to primary care facilities and improvements in some population health indicators have been observed, but social inequities and poor care quality remain. Further research and policy initiatives are needed to address several issues such as rational resource deployment, career progression for contractually hired care providers and ASHA, building health awareness at the grassroots for better community representation, and increased attention to non-communicable diseases, mental health, and the impacts of aging and climate change.