The population of the UNECE region is ageing: one in four people will be 65 years old or above by 2050 compared to one in six today. Population ageing has social and economic implications for which societies need to prepare. This requires a coordinated, whole-of-government and whole-of-society effort to bring societies and economies into harmony with demographic change, otherwise known as ‘mainstreaming ageing’. A more effective integration of ageing into all policies at all levels will enhance societal preparedness for population ageing and benefit all age groups. This Policy Brief highlights seven key ‘enablers’ for mainstreaming ageing: political and executive leadership, strategic frameworks, governance and coordination mechanisms, age-sensitive analysis and impact assessments, capacity development, enhanced awareness, data and analysis to inform policies, and participatory policymaking.