BACKGROUND:
Nigeria bears the highest malaria burden globally, accounting for roughly one-quarter of global cases and nearly one-third of deaths. Although malaria transmission occurs nationwide, it is highly heterogenous across ecological zones, states and local government areas. Historically, malaria interventions were planned and financed using largely uniform national approaches, limiting efficiency and impact particularly under increasing resource constraints. Subnational tailoring (SNT) has emerged as a critical strategy for aligning interventions with local risk, health system capacity, and financing realities.

METHODS:
This study examined Nigeria’s experience institutionalizing SNT within national malaria policy and planning. A mixed-methods design combined desk review of policies, partner documents, quantitative analysis of malaria trends, intervention and financing data; and qualitative analysis of 31 key informant interviews conducted at national and subnational levels. Six states were selected as case studies reflecting epidemiological diversity and differing financing contexts. An adapted conceptual framework guided analysis across three domains: generating, synthesizing and acting on the evidence.

RESULTS:
Findings show substantial progress in embedding SNT into malaria decision-making in Nigeria. The launch of the National Malaria Data Repository in 2020 strengthened data integration and accountability, while stratification and modelling informed prioritization of intervention mixes. SNT supported major programmatic shifts, including expansion of seasonal malaria chemoprevention, targeted deployment of next-generation insecticide-treated nets, and more efficient allocation of resources during funding reductions. However, persistent challenges remain, including uneven data quality, limited subnational analytic capacity, fragmented financing and weak translation of evidence into sustained political commitment.

CONCLUSIONS:
Nigeria’s experience demonstrates that SNT isn't merely a technical tool but a governance and systems reform that improves efficiency, accountability and equity in malaria programming. Sustaining these gains will require investment in subnational analytic capacity, stronger data stewardship and systematic integration of SNT into routine planning, budgeting and accountability mechanisms. These offer guidance for high-burden, resource-constrained settings.