Pedagogy for socially accountable medical professionalism lacks systematic integration of relevant social and biomedical facts. A sociological gaze and change in medical discourse may be transformative. A mixed methods study compared perceptions of social justice in healthcare of forty medical student participants from diverse social positions enrolled in two Australian medical schools. The ‘capability to aspire’ to prosocial professionalism links Sen’s capability theory and Bourdieu’s theory of practice to compare outsiders and insiders in a traditional and a socially accountable program. Comparison of First and Final Year cohorts aimed to identify the regulative discourses of each program. Demographic, short answer and multi-choice questions, and semi-structured audio-recorded interview tested participants’ aspirations, knowledges and reasoning related to social accountability. All cohorts supported social justice learning and agreed Indigenous, refugee and migrant groups were most disadvantaged in Australian health care. Final Year participants had greater awareness of health system shortfalls in social accountability, citing professional discourses lacking equity awareness, unfair patient responsibilisation, system overload and mismatch to Indigenous health needs. Less intention to practice in areas of health need was shown by participants with zero and multiple devalorised social identities than those with single equity identities. A common finding was inability to modify clinical reasoning to recognise what matters for equity needs, making ‘health equity’ a threshold concept. Critical reflexivity on human contexts of illness production was best realised by outsiders, unrelated to program. International participants held stronger perceptions of mismatch between the Australian health system and Indigenous health needs. Results inform a socio-science approach to learning health equity that builds on students’ prosocial values, social identities, and meaning-making of social contexts. A re-contextualising principle to validate health equity perspectives in medical pedagogy, and knowledge management system to integrate social and medical discourses, are proposed. The potential benefits of biosemiotic, edusemiotic and semioethic approaches to the humanising turn in medical education are discussed. Legitimation Code Theory provides a means to systematise diverse discourses in medical education. Biosemiotic concepts of lifeworld and dialogical communication may further cultivate students’ sociological and moral imagination of health production, and creativity for socially accountable solutions to emergent illness.