This report examines the patterns of teacher attrition among full-time teachers in Indiana from 1965 to 1987. The study's objectives were to assess the current state of teacher supply and demand in Indiana, recommend policies to ensure an adequate supply of certified teachers, and provide the Indiana State Department of Education with the capability to monitor and perform future assessments of teacher supply and demand. The introduction outlines a rationale for the study and provides definitions of attrition. The report goes on to present and discuss a theory of teacher attrition, to examine trends in attrition in Indiana and patterns of attrition among new teacher cohorts, and to analyze attrition over the career and over the first four years after entry using multivariate analysis. Study findings include, among others: (1) both annual and permanent teacher attrition rates have fallen steadily over time with the exception of a period in the late 1970s characterized by involuntary reductions in staff; (2) attrition in entering cohorts of new teachers is at its lowest level in 25 years; and (3) lower attrition of women teachers during early to mid-career accounts for a significant portion of the overall attrition decline. An appendix provides regression estimates for Cox models of teacher attrition. The main report is preceded by a substantial summary of its contents.