This study investigates the generalisability of pathways depicted by causal loop diagrams (CLDs) in payment for performance (P4P) schemes by adapting and validating the Tanzanian CLDs to the Zambian context. Specifically, it explores whether the health system pathways represented by CLDs, are consistent across different settings and how variations in programme design and local context influence these pathways. Using a five-stage approach, the study adapted the Tanzanian CLDs to reflect the Zambian P4P programme context, validating them through stakeholder interviews, workshops, and secondary qualitative data. The findings show that while the overarching pathways influencing P4P outcomes are similar, differences in programme design and contextual factors shape their intensity and impact. Notably, Zambia's higher facility autonomy and stronger trust in the health system contributed to greater health worker motivation and service delivery compared to Tanzania. Programme design features such as safeguards for non-incentivised services and adequate funding for facility investment with provider autonomy influenced performance outcomes. Additionally, contextual factors such as trust in the system mitigated programme delays, while decentralised procurement systems enhanced P4P effectiveness. These findings highlight the need for context-specific adaptation when implementing P4P programmes. The study advances the application of CLDs for cross-country health system analysis, highlighting both their potential and limitations in comparing health interventions across diverse settings.