Background & Aims: As Australia’s population ages, individuals aged 55+ are increasingly important for Blood Collection Agencies (BCAs) to help sustain the blood supply. While donation may offer psychosocial benefits for older adults, little is known about how older donors experience stopping donation, whether through permanent deferral (PD) imposed by BCAs or voluntary self-deferral (SD). This study explored how older donors experience and respond to stopping donation, and the effects on identity, emotional well-being, self-perceptions of ageing, sense of purpose, and social connectedness. Methods: Thirty semi-structured interviews were conducted with donors aged 55+ who had recently stopped donating (PD=22; SD=8). Data were analysed using reflexive thematic analysis informed by Role Identity Theory and Stereotype Embodiment Theory. Results: Participants described donation as a meaningful way to contribute to society, fulfil moral obligations, and affirm health and capability in older age. Loss of the donor role evoked emotional responses, ranging from relief to disappointment and profound loss, with some participants only realising the depth of their donor identity after stopping. Although most understood the safety reasons behind their deferral, some felt the process was abrupt and wanted clearer communication or greater opportunity for discussion before the decision was finalised. Conclusion: Stopping blood donation can have psychosocial consequences for older people. Consistent with Role Identity Theory, the loss of a valued role may undermine purpose and identity in later life, helping explain feelings of disappointment following deferral. Improving how deferral is communicated may better support older donors through the transition to no longer donating.