Latent classes of effective and non-effective Algebra I teachers were established using measurements of teacher promoted engagement, teacher promoted understanding, and classroom management from the Measures of Effective Teaching Project (MET Project) database. Historically, robust measures of effective teaching exist in the literature; however, there are no sets of factors or attributes that define an effective teacher. Instead, current teacher accountability practices have weighed heavily on observations, student surveys, and standardized test scores in value added models as indicators of teacher effectiveness. This study focused on Algebra I teachers due to the importance of establishing student success in the areas of Science, Technology, Engineering, and Mathematics (STEM). Results support the use of latent class analysis using teacher characteristics to identify effective and non-effective teachers.