AbstractThis article proposes a descriptive model of assessment competence for teachers of Finnish as a Second Language and Literature (FSLL), addressing a research gap in subject-specific language assessment literacy within Nordic contexts. While existing frameworks, such as the teacher assessment literacy in practice (TALiP), provide general principles for teacher assessment literacy, they do not sufficiently account for multilingual environments or the unique challenges of second language learners. Our model integrates pedagogical content knowledge (PCK) with linguistic depth, emphasizing phonology, morphology, and syntax as critical components for FSLL assessment. It also incorporates the concept of assessment culture, highlighting the role of shared practices and collegial support within school communities. Drawing on theoretical foundations (Grossman, 1990; Xu & Brown, 2016) and Finnish curriculum guidelines, the model aligns with the Common European Framework of Reference for Languages (CEFR) principles and promotes functional language use. We argue that FSLL teachers require comprehensive subject knowledge and the ability to apply it in assessment practices that support learning, fairness, and equity. The model aims to guide teacher education and professional development, offering a framework for reflective practice and collaborative assessment culture. Future research should examine its applicability in classroom contexts and explore its potential adaptation to other languages.