This research investigated consistency of achievement levels stated in the 2015 revised national curriculum of English, high school English textbooks, and the Korean College Scholastic Ability Test (CSAT) according to CEFR Levels. Based on CEFR levels, this study compared levels of targeted achievement standards in the national curriculum, focusing on reading passages in High School EnglishⅡ and CSAT implemented for three consecutive years (2021-2023). Results indicated that the reading section of textbooks and CSAT included a considerable portion of passages whose text difficulty levels were higher than CEFR B2, exceeding the achievement standards required for high school graduates. These results suggest that difficulty levels in the national curriculum, textbooks, and CSAT should be adjusted according to target levels of language proficiency based on CEFR levels so that learning burden of students can be lessened and competency-based English teaching and learning finally can be performed.