The objectives of this study aretwo-fold. First, it presents the basics of assessing workingage populations for disability benefits. Increasingly, theoperational staffs of the World Bank Group (WBG) and theWorld Health Organization (WHO), as well as of otherdevelopment organizations, are being requested bygovernmental policy agencies for technical advice andassistance on how to reform their disability assessmentsystem. Secondly, while acknowledging limitations, both inconception and implementation; it makes a case for whyadopting the international classification of functioning,disability, and health (ICF) approach to disabilityassessment may be smart policy that corresponds well withthe aims of modern disability policy that focuses on socialand economic inclusion for individuals with disabilities, inthe context of a recognition of their fundamental humanrights. The study is a follow up work to the world report ondisability that WHO and WB published jointly in June 2011.The world report made it clear that the process ofdisability assessment is an important lever of disabilitypolicy in any country, yet little is known about howdisability assessment is conducted. This study responds tothat knowledge gap, but it also describes a paradigm shiftin the assessment of disability, one that moves fromprevailing impairment and functional limitation approachesto a disability-based approach.