Why are medical errors so common? We identify primary sources of medical error as system factors (both local workplace policies and procedures and broader societal and governmental requirements and technological advancements), teamwork factors, and individual factors. These three levels of influence interact and operate concurrently as healthcare providers are working with their patients. Each is a potential primary source of a medical error, but as in other HROs, error rarely has a single “cause.” Poorly designed systems can make it more difficult for teams to operate effectively and for individual healthcare providers to avoid mistakes. As much as all three levels of influence over safe practice are important, it ultimately comes down to the safe individual, the doctor who is “fit for duty.” They can operate effectively, contribute to team performance (help identify and correct the errors of others), and, as needed, lobby for improved policies and procedures. Again, the pandemic has added significant stress to the healthcare provider, calling for solutions at all three levels, addressing all three potential sources of error.