As more attention is placed on designing digital educational games to align with schools' academic aims (e.g., Common Core), questions arise regarding how professional development (PD) may support teachers' using games for instruction and how such integration might impact students' achievement. This study seeks to (a) understand how teachers use PD resources (e.g., technology personnel and game-use workshops) for integration; (b) determine how teachers integrate games into their instruction; and (c) examine how those teaching practices are associated with student achievement. This mixed method study used survey and interview responses from elementary school teachers (n = 863) with access to PD resources for implementing a math game intervention and standardized math-test scores from their second- through sixth-grade students (n = 10,715). Findings showed few teachers sought PD assistance for integration, but many desired such support. Some reported using integrative practices (i.e., referencing game and using game-generated progress reports) to identify struggling students, whereas several found integration challenging. Teachers' reordering of game objectives to align with lessons and viewing of game-based PD videos were associated with increased student math achievement in our OLS-analysis. However, this result was no longer statistically significant within a school fixed-effects model, suggesting school differences may influence how strongly teachers' practices are associated with student achievement.