The Common Core State Standards (CCSS) for English language arts and mathematics represent a sea change in standards-based reform and their implementation is the movement's next--and greatest--challenge. Yet, while most states have now set forth implementation plans, these tomes seldom address the crucial matter of cost. Putting a Price Tag on the Common Core: How Much Will Smart Implementation Cost? estimates the implementation cost for each of the forty-five states (and the District of Columbia) that have adopted the Common Core State Standards and shows that costs naturally depend on how states approach implementation. Authors Patrick J. Murphy of the University of San Francisco and Elliot Regenstein of Education Counsel LLC illustrate this with three models: (1) Business as Usual; (2) Bare Bones; and (3) Balanced Implementation. The report examines the tradeoffs associated with each strategy and estimates how much the three approaches would cost each state that has adopted the Common Core. The authors also point out that, since states already invest billions annually in professional development, assessments, textbooks, and other expenses in connection with existing standards, proper forecasting of Common Core costs should "net out" the sums that states would spend anyway for activities that this implementation process will replace. Appended are: (1) Technology in Common Core Implementation; (2) District Budget Estimates; (3) Data Sources; and (4) States' Common Core Resources. (Contains 9 tables and 93 endnotes.) [This report was written with Keith McNamara. Foreword by Chester E. Finn, Jr. and Amber M. Winkler.]