U.S. teachers take off an average of 9.4 days (roughly 1 day per month) each during a typical 180-day school year. By that estimate, the average child has substitute teachers for more than six months of his school career. The education department reported after the 2003-04 school year that 5.3 percent of U.S. teachers are absent on any given day, and that's still the number most researchers use. In the education department's 2009-10 report--assembled by its Office for Civil Rights from surveys of 57,000 schools--on average, half the teachers in the 208 Rhode Island schools surveyed were absent more than 10 days during the year, surpassing teacher absences in Hawaii, Arkansas, Oregon, and New Mexico by only a whisker. Nationally, 36 percent of teachers were absent that often. And even in Utah, which reported the lowest absence rates to the department, 20 percent of teachers took off more than 10 days each school year. Gleaning from research results from Harvard's Raegen Miller, Richard Murnane, and John Willett and Duke University's Charles Clotfelter, Helen Ladd, and Jacob Vigdor, this article discusses the demographics of teachers who take the most leave and their reported reasons for their absences. Additionally, statistics from the National Council on Teacher Quality and study results from Columbia researchers Mariesa Herrmann and Jonah Rockoff support an examination of the impact of these absences, the use of substitute teachers, the cost to learning, and different systems used by different schools to lessen that impact.