The latest data from the Millennium Cohort Study (MCS) is now available from the UK Data Service. This release covers the Age 23 sweep, which includes information collected from more than 9,700 study participants between 2023 and 2025.
What is the Millennium Cohort Study?
The Millennium Cohort Study is a UK longitudinal birth study conducted by the UCL Centre for Longitudinal Studies. It follows the lives of around 19,000 children born in England, Scotland, Wales and Northern Ireland in 2000-02. The study tracks measures such as physical, socio-emotional, cognitive and behavioural development, economic circumstances, parenting, relationships and family life.
There have been eight main sweeps of the study. The Age 23 sweep was based on a 60-75-minute questionnaire that was completed either online or face-to-face. The latest questionnaire included some new questions covering topics such as personality and resilience, financial literacy, parenthood and fertility plans, and expectations for the future.
The Millennium Cohort Study is the only nationally representative cohort study for Generation Z available in the UK. This latest release provides invaluable insights into the diverse experiences of this age group as they make the transition into adulthood.
Access the data
You can access the main dataset as well as selected sensitive data via our data catalogue. A second data release is scheduled for April 2026 that will include data partner data, geographical indicators and more detailed education measures.
More information on what’s changed in the Age 23 sweep is available from the MCS Age 23 Sweep page at the Centre for Longitudinal Studies website, which also includes a user guide as well as the questionnaires and other documentation of the data and fieldwork.