This article aims to understand why religion has proven difficult to address in secular healthcare, although existential communication is important for patients’ health and wellbeing. Two qualitative data samples exploring existential communication in secular healthcare were analyzed following Interpretative Phenomenological Analysis, leading to the development of the analytical constructs of ‘the secular’ and ‘the non-secular’. The differentiation of the secular and the non-secular as different spheres for the individual to be situated in offers a nuanced understanding of the physician–patient meeting, with implications for existential communication. We conceptualize the post-secular negotiation as the attempt to address the non-secular through secular activities in healthcare. Employment of the post-secular negotiation enables an approach to existential communication where the non-secular, including religion, can be addressed as part of the patients’ life without compromising the professional grounding in secular healthcare. The post-secular negotiation presents potential for further research, clinical practice, and for the benefit of patients.