Accounting professionals are frequently interrupted, and prior research suggests that task interruption could compromise the quality of their professional judgments. This paper adopts the Goal-Based Choice Model to predict conditions under which task interruption will: (1) exacerbate accountants' motivated reasoning, introducing bias into their professional judgments, and (2) reduce performance on the interrupting task. We validate the model by conducting an experiment using experienced tax professionals as participants. Consistent with the expanded model's predictions, we find that when tax professionals are highly committed to a directional goal (minimize the client's tax liability), task interruption exacerbates their motivated reasoning, increases their perceptions of the level of support for an aggressive tax compliance position, bolsters their confidence in its defensibility, and compromises their ability to objectively evaluate the risks associated with the position. These factors cascade to increase the likelihood that they will recommend an aggressive tax compliance position. Furthermore, we find that the impact of task interruption cascades to inhibit interrupting task performance. Our results suggest that task interruption can create costly inefficiencies when these issues must be addressed during the review process, and that severe consequences for firms and their clients can arise when the review process fails to identify these deficiencies. In addition, our results suggest that task interruption's costs may outweigh its benefits in the context of professional judgment.