This twelfth edition of "Measuring up to the Model: A Ranking of State Charter School Laws" evaluates each state's public charter school law against the 21 essential components of a strong charter school law. These 21 components are drawn from the National Alliance's "A New Model Law for Supporting the Growth of High-Quality Public Charter Schools: Second Edition" (ED613003). Key takeaways include: (1) For the sixth year in a row, Indiana has the nation's strongest charter school law in the country, ranking No. 1 (out of 45); (2) The Top 10 includes a mixture of states with more mature movements (Indiana at No. 1, Colorado at No. 2, Minnesota at No. 4, Florida at No. 7, Louisiana at No. 8, and the District of Columbia. at No. 101) and states with newer movements (Washington at No. 3, Alabama at No. 5, Mississippi at No. 6, and Maine at No. 9); (3) States that are enacting laws for the first time and states that are overhauling their laws are bypassing states that were previously more highly ranked, such as Massachusetts, Arizona, and New York; and (4) Maryland has the nation's weakest charter school law, ranking No. 45 (out of 45). [For the eleventh edition, see ED609763.]