Climate change poses a growing threat to agricultural livelihoods, particularly for smallholder farmers who face reduced productivity and income. This study examines the complementarities among climate change adaptation strategies (CCAS) and their impact on net farm income (a proxy for productivity) among smallholder maize farmers in South Africa. Using a multistage sampling technique, data were collected from farmers across 30 villages. Analytical methods included the Multivariate Probit (MVP) model to assess the determinants and complementarities of CCAS, the Endogenous Switching Regression Model (ESRM) to estimate the impact of CCAS on farm income, and the Negative Binomial Regression Model (NBRM) to capture count data characteristics. The results reveal that 73 % of household heads were married, with an average age, household size, and farm size of 45 years, 4 persons, and 3.26 hectares, respectively. These demographics suggest a relatively mature and stable farming population, influencing adaptation decisions. The ESRM findings indicate that household size (β = -0.227; p < 0.05), educational level (β = 0.819; p < 0.01), and farm size (β = 0.101; p < 0.01) significantly affect CCAS adoption. Adopters of CCAS realized a significant increase in net farm income (approximately $3689.19 per hectare), highlighting the economic gains from adaptation. The study concludes that smallholder productivity is significantly influenced by both the type and combination of adaptation strategies, which are shaped by socioeconomic and institutional factors. Policies that enhance education, extension services, and credit access while promoting integrated adaptation strategies are essential to bolster smallholder resilience and ensure sustainable food systems amid ongoing climate variability.