Interactive writing is an instructional practice widely considered effective and most appropriate for emergent writers. This article asserts that it is a valuable method for more fluent writers in grades 2-5. It outlines the basic lesson sequence and proposes four key shifts to adapt interactive writing for older, more fluent writers: 1) The lesson sequence is more fluid and dynamic; 2) Elements of Share the Pen are modified; 3) Lessons decrease in frequency while increasing in length; and 4) Teaching points expand and extend around genre. Four universal principles that hold across all grades are further elaborated: 1) Value each step in the lesson; 2) Balance the planned and unplanned teaching opportunities; 3) Make intentional teaching decisions as students develop; and 4) Make explicit links between a whole class lesson and students' own writing. Recommendations for implementing interactive writing in upper-elementary grades are suggested.