We examine trends in household disposable income inequality and potential mechanisms shaping inequality through changes to work, wages, earnings, marriage, and the tax and transfer system in the United States over the nearly five-decade period from 1975 to 2022. Overall after-tax and transfer income inequality increased more than 25 per cent since the mid-1970s, and by as much as 50 per cent when comparing the 90th and 10th percentiles.