Aim: This investigation aims to bring a reflection on the various expressions of old age heterogeneity, associated with the active participation of the older people in Residential Structures for the Older People (ERPI) and in their life project. Method: The sample involved 12 older people and five Social Workers who lived and practiced their profession in ERPI, respectively. The protocol consisted of a Sociodemographic Questionnaire, and (semi-structured) In-Depth Interviews, using a qualitative approach (content analysis methodology). Results: In the sample of older adults, the majority were "old-old" adults (> 85 years old). Concerning participation in ERPI decision-making processes, older people voluntarily refused to contribute to the decisions allocated to the institutional dynamics/strategies. Regarding the position adopted by ERPIs, even though they assume a directive pattern associated with care, provisions having a more innovative nature (e.g., older people's committee, bibliotherapy, social gatherings) begin to emerge, converging with current approaches of active aging, in which, older people are recognized as a heterogeneous group. This fact is in line with the senior citizens' fulfillment that arises from the opportunity they are given to exercise their citizenship daily. Conclusions: Institutional care tends to favor a holistic/global approach to understanding old age heterogeneity. These changes, although assuming a slow and monotonous pace, lead to operational approaches capable of privileging the knowledge and wisdom of the older people, actively involving them in decision-making processes in collective residential contexts, associated with the contemporary active aging movements.