Teachers' attitudes and beliefs play an important role in their integration of digital games in the classroom thus the transformative potential of game-based learning. In this study, we adapt the Technology Acceptance Model to examine elementary teachers' acceptance of a digital mathematics game and investigate antecedents to their intention to use the game to teach mathematics. The hypothesized extension of Technology Acceptance Model includes redefined factors in the context of game use during mathematics instructions (perceived ease of use, attitude towards game use, perceived usefulness for mathematical learning), a social factor (environmental support), and specified outcome factors depending on orientations (game-driven intention, mathematics-driven intention). Using survey data from 304 elementary teachers in the USA, the findings confirm associations within the adapted model, including direct links from attitudes and environmental support towards intentions to use the digital game and indirect links from perceived ease of use and usefulness. Implications for acceptance theories and teaching practices to use digital games are discussed.