Longitudinal data are used to estimate retirement income replacement rates of employees in Ireland who transition into retirement over the period 2010 to 2014. The median replacement rate is estimated at 50 per cent, with the mean at 78 per cent. The mean estimate seems high relative to stated policy goals but further analysis shows that the estimate results in part from very high replacement rates at the lower end of the income distribution. This in turn results from the flat-rate nature of social welfare pensions in Ireland. More broadly, Ireland's pension system is shown to produce a more equal distribution of replacement rates compared to pre-retirement income. However, this leads to a question as to whether policy goals in the areas of pension adequacy should be set with respect to income or consumption levels as opposed to replacement rates.