IMPORTANCE The mean cost of medical care in the United States is growing at an unsustainable rate; from 2003 through 2011, the cost for an emergency department (ED) visit rose 240%, from $560 to $1354. The diagnostic tests, treatments, and hospitalizations that emergency clinicians order result in significant costs. OBJECTIVE To create a "top-five" list of tests, treatments, and disposition decisions that are of little value, are amenable to standardization, and are actionable by emergency medicine clinicians. DESIGN, SETTING, AND PARTICIPANTS Modified Delphi consensus process and survey of 283 emergency medicine clinicians (physicians, physician assistants, and nurse practitioners) from 6 EDs. INTERVENTION We assembled a technical expert panel (TEP) and conducted a modified Delphi process to identify a top-five list using a 4-step process. In phase 1, we generated a list of low-value clinical decisions from TEP brainstorming and e-mail solicitation of clinicians. In phase 2, the TEP ranked items on contribution to cost, benefit to patients, and actionability by clinicians. In phase 3, we surveyed all ordering clinicians from the 6 EDs regarding distinct aspects of each item. In phase 4, the TEP voted for a final top-five list based on survey results and discussion. MAIN OUTCOMES AND MEASURES A top-five list for emergency medicine. The TEP ranked items on contribution to cost, benefit to patients, and actionability by clinicians. The survey asked clinicians to score items on the potential benefit or harm to patients and the provider actionability of each item. Voting and surveys used 5-point Likert scales. A Pearson interdomain correlation was used. RESULTS Phase 1 identified 64 low-value items. Phase 2 narrowed this list to 7 laboratory tests, 3 medications, 4 imaging studies, and 3 disposition decisions included in the phase 3 survey (71.0% response rate). All 17 items showed a significant positive correlation between benefit and actionability (r, 0.19-0.37 [P ≤ .01]). One item received unanimous TEP support, 4 received majority support, and 12 received at least 1 vote. CONCLUSIONS AND RELEVANCE Our TEP identified clinical actions that are of low value and within the control of ED health care providers. This method can be used to identify additional actionable targets of overuse in emergency medicine.