Traditional defined benefit pensions, once a major source of retirement income, are increasingly giving way to tax-qualified defined contribution (DC) plans and individual retirement accounts (IRAs). This trend is likely to continue among future retirees who have worked in the private sector. This article discusses the implications of those trends for the measurement of retirement income. We conclude that Census Bureau’s Current Population Survey (CPS), one of the primary sources of income data, greatly underreports distributions from DC plans and IRAs, posing an increasing problem for measuring retirement income in the future. The CPS and other data sources need to revise their measures of retirement income to account for periodic (irregular) distributions from DC plans and IRAs.