Studies have indicated that self-regulated learning is critical for 21st century learners and lifelong learners, and it can also explain students' learning outcomes. In the current learner-centered instruction, especially in online learning environments, self-regulated learning has become a more critical element for students' success. Given the previous findings that self-regulated learning is teachable, this study attempted to examine what kinds of supports teachers at U.S. K-12 online schools provided to their students to develop self-regulated learning skills and how teachers provided those supports. The roles of technology in such teachers' practices were also examined. The results showed that teachers provided students with more direct guidance instead of helping them understand and develop self-regulated learning by themselves. Implications for practices to support the development of students' self-regulated learning, such as personalization, learning community, and balance between teacher-regulated learning and self-regulated learning were discussed.