This study reports how extensive reading (ER) teachers implemented ER and used reading materials at institutions in formal educational systems in Japan, Mongolia, Thailand, and Vietnam. 259 participants completed an online questionnaire. The results revealed that ER was mainly required and done online in Japan and Mongolia while it was optional but recommended and mainly paper-based in Thailand and Vietnam. The majority of the participants assessed their students' reading and did post-reading activities. The top three sources of funding came from the participant's school, the students, and the use of free materials. About 40% of the responses indicated the use of graded reading materials and 60% were the use of non-ER materials such as picture books, native novels, textbooks or academic works, despite the vast majority of their students being intermediate level or lower. The implications and limitations of these findings are discussed to highlight proposals for future studies.