As noted earlier, elementary schools were using WAC before they knew what it was, and secondary has moved beyond the original conception of WAC in much the same way that higher education has. In the 21st century, WAC in U.S. K-12 schools has been elevated through acknowledgment on a federal level by initiatives and publications such as Common Core State Standards (CCSS), Frameworks for Success in Postsecondary Writing (CWPA, NCTE & NWP, 2011), and Framework for Information Literacy for Higher Education (ACLR, 2015). Cross disciplinary teachers in K-12 schools are aware of the CCSS through its specifications of competencies their students must meet before high school graduation. For instance, in the CCSS for grade 3 mathematics, students must be able to "construct viable arguments and critique the reasoning of others"; while high school algebra students must "construct a viable argument to justify a solution method." These examples demonstrate how writing to learn and other WAC-based principles contribute to meeting disciplinary CCSS successfully. Teachers preparing their students for postsecondary coursework are working to meet both of the Framework documents mentioned above by using more sophisticated WAC skills to support student learning. Whether working through discipline-specific or cross disciplinary courses, or by working with WAC-based writing centers, K-12 teachers are using and will continue to use collaborative writing and WAC in mathematics, science, history, art, foreign language, or other disciplinary areas outside English and language arts. As a student-centered movement, WAC fulfills one of the criteria in the ACLR Framework (2015) by encouraging students to ask "increasingly complex new questions whose answers in turn develop additional questions or line of inquiry in any field" ("Research as Inquiry"). These kinds of specific connections to WAC can be found in every discipline, such as science, where the American Association for the Advancement of Science provides guidance on the use of writing in STEM courses (Atlas of Science Literacy, 2011).
As WAC continues to increase its impact in K-12 institutions, schools of education in postsecondary institutions must also evolve. Most higher education literacy programs now emphasize the teaching of writing in courses for instructors at every level, from K-12 pre-service programs through graduate programs. The current and future K-12 teachers taking these courses, in turn, apply WAC pedagogies they have learned to their work as teachers (see Tremmel & Broz, 2002). Teachers across disciplines are also discovering how essential WAC theory and practice have become in their online teaching as, during the COVID-19 pandemic, they have had to move away from face-to-face teaching to hybrid and online teaching.
WAC promises to become an even more vital movement in K-12 education, especially in online instruction, where breakout sessions include response to writing by peers and forums offer exchanges of ideas. In addition, writing-to-learn and writing-to-engage (Palmquist, 2021b) activities connect to experiments, readings, descriptions, critical explanations, and metacognitive approaches to learning in all disciplines. As issues of systemic racism, poverty, and trauma are crying out for writing as social action and self-discovery at all academic levels, WAC as a movement will continue to adapt and have a place in K-12 institutions. During these new global challenges, K-12 and postsecondary educators must share what they have found as successful uses of WAC and continue partnerships for greater faculty development at all academic levels. Mullin and Childers (2020), for example, argue that WAC in K-12 schools should continue to support curricular change that benefits students and faculty and "collaborate more widely, aggregate data on best practices, and disseminate information more effectively."