BACKGROUND: The Millennium Development Goals expire at the end of 2015 and global negotiations are underway to finalise the post-2015 Sustainable Development Goals. Much activism has occurred encouraging a post-2015 health and development goal embedded in the highest attainable standard of health ('right to health'). Despite this, the right to health was absent in three key post-2015 intergovernmental Sustainable Development Goal proposals in 2014, one of which was reinforced by the United Nations General Assembly in September 2014 as the guiding document for ongoing interstate negotiations. This article examines why it appears the right to health, so far, is not gaining direct expression in post-2015 discussion. METHODS: This qualitative research is part of a broader study using thematic and discourse analysis examining the high-level policy debate on health goals in the discourse of the formulation of the post-2015 Sustainable Development Goals. Key-informant interviews were conducted in two interview rounds in 2013 and 2014, with participants from multilateral and other organisations (government, academia, civil society and philanthropy) responsible for health in the post-2015 development agenda (or the post-2015 development agenda more broadly). This study synthesises data from both interview rounds on Health and Human Rights in post-2015 Sustainable Development Goal negotiations. RESULTS: Six reasons why the right to health may not have gained effective traction in the unfolding post-2015 Member State negotiations were found. The first three reasons relate to broader issues surrounding human rights' (including sexual and reproductive health and rights) positioning within international relations discourse, and the second three relate to the challenges of transforming the human right to health into a practically applied post-2015 health goal. CONCLUSIONS: This paper reports the views of participants, many of who sit at the interface of United Nations and Member State negotiations, on the right to health's location (and projected trajectory) at two temporal junctions in evolving post-2015 negotiations. The interviews provide insight into high-level hesitancy that the right to health be expressly incorporated in the final post-2015 health and development goal, as well as documents participants' doubt that rights language will explicitly frame the broader Sustainable Development Goals, their targets and indicators.