Widespread adoption of the Common Core State Standards (CCSS) in the United States has resulted in an unprecedented set of national secondary school writing standards that shift responsibility for writing instruction across content areas. As secondary school teachers grapple with these new demands, this article proposes that WAC can serve as a key resource in helping content area teachers implement and adjust CCSS-driven writing instruction. If secondary WAC advocates are to be successful in responding, however, they must first address the roadblocks that present challenges for secondary school content area teachers. By drawing on WAC's long history as well as those existing but limited examples of secondary school-wide WAC initiatives that offer concrete illustrations of what is possible, secondary WAC advocates can seize the opportunity of this unique historic moment to help teachers and students by offering models for future secondary school WAC growth and understanding.