How do International Monetary Fund (IMF) policy reforms-so-called 'conditionalities'-affect government health expenditures? We collected archival documents on IMF programmes from 1995 to 2014 to identify the pathways and impact of conditionality on government health spending in 16 West African countries. Based on a qualitative analysis of the data, we find that IMF policy reforms reduce fiscal space for investment in health, limit staff expansion of doctors and nurses, and lead to budget execution challenges in health systems. Further, we use cross-national fixed effects models to evaluate the relationship between IMF-mandated policy reforms and government health spending, adjusting for confounding economic and demographic factors and for selection bias. Each additional binding IMF policy reform reduces government health expenditure per capita by 0.248 percent (95% CI -0.435 to -0.060). Overall, our findings suggest that IMF conditionality impedes progress toward the attainment of universal health coverage.