As students and educators head back for another pandemic-disrupted school year, the third and final edition of Quality Counts 2021 provides a broad perspective on the nation's K-12 system, with summative grades and scores for the U.S. and each state on a range of academic, financial, and socioeconomic indicators that underlie student achievement and long-term prospects for success. The report also includes exclusive EdWeek Research Center analysis of how households of school-age children are faring during the pandemic on key factors affecting student learning based on nationwide U.S. Census Bureau surveys conducted as the most-recent school year came to a close. Articles in this issue include: (1) Editor's Note: Schools Straddle the Pandemic and Familiar Headwinds in Quest to Boost Quality; (2) Nation Gets a 'C' on Latest School Quality Report Card, While N.J. Again Boasts Top Grade (Sterling C. Lloyd and Alex Harwin); and (3) Households With School-Age Kids See Continued Educational Hurdles as Pandemic Drags On (Alex Harwin and Sterling C. Lloyd). [For the first installment "Quality Counts 2021: Chance for Success," see ED610740. For the second installment "Quality Counts 2021: School Finance," see ED617405.]