Livelihood diversification is widely viewed as a key pathway for enhancing rural resilience in contexts marked by environmental stress and agrarian uncertainty. This paper examines whether India’s National Rural Livelihoods Mission (NRLM), the world’s largest poverty-alleviation program, contributes to livelihood diversification among rural households in Assam, a flood-prone and agriculture-dependent state in Northeast India. Drawing on primary household survey data from three districts representing upper, middle, and lower Assam, the study compares livelihood portfolios of NRLM participants and nonparticipants. The results show that program participation is positively associated with greater diversification into nonfarm wage employment, self-employment, and service activities alongside agriculture. Education, skill training, proximity to urban centers, and engagement in nonfarm occupations significantly shape diversification outcomes. Women’s participation through Self-Help Groups emerges as a critical institutional mechanism facilitating access to skills, credit, and collective learning. The findings suggest that NRLM contributes to rural resilience primarily by strengthening institutional and human capital rather than through income effects alone. The paper highlights the importance of place-specific infrastructure and skill investments for enhancing the diversification impacts of large-scale livelihood programs in environmentally vulnerable regions.