Purpose We present a case report detailing a challenge in health information technology (HIT) project implementations we term “stakeholder creep”: not thoroughly identifying which stakeholders need to be involved and why before starting a project, consequently not understanding the true effort, skill sets, social capital, and time required to complete the project. Methods A root cause analysis was performed post-implementation to understand what led to stakeholder creep. HIT project stakeholders were given a questionnaire to comment on these misconceptions and a proposed implementation tool to help mitigate stakeholder creep. Findings Stakeholder creep contributed to an unexpected increase in time (3-month delayed go-live) and effort (68% over expected HIT work hours). Four main clinician/researcher misconceptions were identified that contributed to the development of stakeholder creep: 1) that EHR IT is a single group; 2) that all EHR IT members know the entire EHR functionality; 3) that changes to an EHR need the input of just a single EHR IT member; and 4) that the technological complexity of a project mirrors the clinical complexity. HIT project stakeholders similarly perceived clinicians/researchers to hold these misconceptions. The proposed stakeholder planning tool was perceived to be feasible and helpful. Conclusions Stakeholder creep can negatively affect HIT project implementations. Projects may be susceptible to stakeholder creep when clinicians/researchers hold misconceptions related to HIT organization and processes. Implementation tools, such as the proposed stakeholder checklist, could be helpful in preempting and mitigating the effect of stakeholder creep.