'Threshold concepts' have recently been identified as a key component for higher or university level teaching in science communication, concepts which can offer a 'transformative' experience amongst students, whilst also creating a sense of discomfort. In this research article, we examine data gathered via two qualitative focus groups and a thematic analysis of 14 reflective learning journals conducted during a M.Sc. Science Communication based in the United Kingdom. Analysis of this data showed that all four threshold concepts (deficit model vs public engagement, audience-centred communication, co-production of science and society, and trust) and two learning concepts (learning progressions and community of practice) were represented in this sample. An additional topic area raised by students was around inclusivity and accessibility, which opens a discussion as to whether this should be considered a concept in itself or recognised as integrated into the other threshold concepts. This study supports previous work in identifying key threshold concepts for science communication and education, and how they can be researched. It also suggests that whilst learners share and articulate core experiences around these concepts, they are potentially most useful for those involved in teaching and curriculum design.