The ESRI’s microsimulation model, SWITCH (Simulating Welfare, Income Tax Childcare and Health policies) has been in operation for three decades. The model is developed and maintained by researchers on the Tax, Welfare and Pensions team and is based on data drawn from the Survey on Income and Living Conditions (SILC) which is carried out by the Irish national statistical agency – the Central Statistics Office (CSO). In 2020, the ESRI undertook a project to redesign the model and the underlying software to keep pace with international developments and provide more model flexibility. The updated SWITCH model is now based on the EUROMOD platform, facilitating cross-country comparison, and uses the most recent pre-pandemic data available, SILC 2019. A detailed description and validation of the SWITCH model is available here. This research is funded by the Department of Employment Affairs and Social Protection, the Department of Health, the Department of Children and Youth Affairs, the Department of Finance and the Department of Public Expenditure and Reform.