This chapter presents a research project designed to understand the contribution of the international classification of functioning, disability and health for children and youth (ICF-CY) as a procedure that operationalises the biopsychosocial approach to early childhood intervention (ECI) in Portugal. In Portugal, substantial changes in ECI are closely connected with the development of health, education and economic policies and services that occurred after democratic revolution. As the ICF-CY is regarded as a common language between different disciplines, its use is highly relevant for professionals involved in multidisciplinary ECI team work. After the team meeting where the final functioning profile was settled, the researcher together with the ECI team designed functional goals for the child. To design the goals, a Functional Goals Protocol was used. This assessment-intervention planning procedure reflects a systematic, planned and intentional intervention. Intervention is embedded in natural daily routines, as ECI quality practices recommend.