To assess the impact of the COVID-19 pandemic on health and HIV expenditure, UNAIDS carried out a modelling study on fiscal space for health and HIV. From a sample of 28 countries, three countries—the Democratic Republic of the Congo, Jamaica, and Lesotho—were selected to capture health and HIV expenditure impacts across countries with especially marked differences in burdens of disease (including HIV prevalence), HIV donor dependency, level of economic development, and geographic location. While the three-country sample is too small to permit findings to be generalized to other countries, these analyses are useful for informing UNAIDS’ work to identify some policy positions to minimize the COVID-19 pandemic’s impact on the HIV response.