© 2019 AANA Publishing Inc.. All rights reserved. Medical errors are among the top 3 causes of patient deaths in the United States, with up to 400,000 preventable deaths occurring in hospitalized patients each year. Although improvements have been made in anesthesia patient safety, adverse outcomes continue to occur. This study used thematic analysis to examine anesthesia closed claims that were associated with preventable morbidity and mortality. Investigators determined that 123 closed malpractice claims files from the American Association of Nurse Anesthetists (AANA) Foundation closed claims database involved events that the involved Certified Registered Nurse Anesthetist could have prevented. Factors that were associated with preventable closed claims included communication failures, violations of the AANA Standards for Nurse Anesthesia Practice, and errors in judgment.