A tabbed index divider assembly comprising a folded divider sheet having length and width dimensions where the sheet is folded along a line that bisects the length dimension, forming a folded outside edge and dual binding edges and having at least one slit in the folded outside edge, and an insert sheet having a tab edge with an index tab extending therefrom, said insert sheet sized and adapted to be secured between the folded halves of the divider sheet with the index tab inserted through the at least one slit in the folded outside edge of the divider sheet. The invention includes a method for making the index divider assembly and a kit having the components for assembling a plurality of index dividers.