This case study explores requirements evolution of a medical device system. The study focuses on the analysis of requirements via interviews and document analysis. The mechanical, software, and systems engineering directors were interviewed regarding eight revisions to the design specifications (>1000 total design requirements). Findings suggest 1) change in requirements leadership, 2) market strategy, and 3) requirements writing may lead to requirements change. From analysis, a requirements culture emerged highlighting a need for greater understanding of company requirements cultures in situ.