The language assessment literacy of English language teachers has been one of the topics of discussion in the language testing field. In this article, I focus on the need to expand research constructs and methodologies to understand, in depth, the language assessment literacy for these key players in language assessment. I first explain the need to focus on language teachers and examine current challenges in researching language assessment literacy. Then, I reflect on how post-positivist, interpretive research constructs and methodologies can expand and why they should. If this happens, research might yield more valid, useful data to unveil the complexities of language assessment literacy for language teachers. That data can provide valuable feedback to advance teachers’ professional development through language assessment literacy.