Starting from 2009-2010, the method Colorado uses to calculate the graduation rate is changing. In the past, early and late graduates were folded into the current graduating class. In the new rate, a student is assigned a graduating class that does not change. These early and late graduates are reflected in 3-year, 5-year, 6-year, and 7-year graduation rates based on their assigned anticipated year of graduation.
Therefore, the major change involves a shift to a four-year “on-time” graduation rate. The shift to the new fourth-year “on –time” graduation rate is being made in order to comply with The No Child Left Behind Act of 2001. Under this act, the state of Colorado must move to an accountability system that measures and reports the “on-time” graduation rate. The formula and methodology is based on the National Governors Association (NGA) “Graduation Counts Compact.”
Colorado Department of Education