This study examined one public school system's change in its bell scheduling format from a seven period day to block scheduling. The data collected was from a three year period of the grade 10 students passing the Massachusetts Comprehensive Assessment System exam. Students in Massachusetts must pass the mathematics and English/language arts subject tests in order to receive their diploma. There were 762 total student results that were observed that included one year prior to the change in the schedule and two years after the change in the schedule. There was an increase in the percentage of students passing the graduation required subject tests of over 15% over the first two years of the block scheduling. (Contains 2 tables.)