This past five years has seen a drastic reform in the Malaysian education system. The reform prompts significant changes in teaching and learning and the assessment system. The emphasis on high-stakes examinations were revised and a new assessment system is introduced. In 2021, many high-stake examinations like Uijan Pencapaian Sekolah Rendah (UPSR) and Pentaksiran Tingkatan 3 (PT3) were abolished due to the reason of being ineffective tools to measure students' learning capability. Since the abolishment, the government paved the way by introducing a more progressive and continuous assessment system known as Classroom-Based Assessment (CBA) which gives full autonomy to teachers to assess students by introducing formative assessments. In the context of English Language Education, the CBA is aligned with CEFR. CEFR breathes new ways for teachers to assess students' language progression across a standard international descriptor. This change has resorted in a huge transformation in the teachers' role as CEFR-aligned CBA demands teachers to plan, design, implement, and report the new assessment system in their teaching practices. Hence, a mixed-method study was conducted to explore the teacher's assessment literacy in implementing CEFR-aligned CBA at the micro level. The findings of this study reported that teachers posit a low assessment literacy level which has influenced their practices to enact the new assessment system. Several challenges like the time constraint, lack of training, teachers' unfamiliarity, and tedious process of CBA raised the concern for the government to reduce these deficiencies in enacting the change in education.