Objective: Combine test theory with technology to develop brief, reliable suicide risk measures in the emergency department. Methods: A computer adaptive test for suicide risk was built using the Beck Scale for Suicide Ideation and tested among the emergency department population. Data were analyzed from a sample of 1,350 patients in several Massachusetts emergency departments. The test was built as outlined by the National Institutes of Health Patient-Reported Outcomes Measurement Information System. Results: Of 1,350 patients, 74 (5%) scored above the cutoff of BSS > 2. Item 2, “Wish to die”, was the most informative item. When using only Item 2, 20% (n = 15/74) of at-risk patients and 3% (n = 40/1,276) of not-at-risk patients were misclassified. Patients were classified after four items with computer adaptive testing trait estimates highly comparable to those of the full scale. The precision rule model did not reduce the scale. Conclusions: This study models the creation of a computer adaptive test for suicide ideation and marks the start of the development of computer adaptive tests as a novel suicide risk screening tool in the emergency department. Computer adaptive tests hold promise for revolutionizing behavioral health screening by addressing barriers including time and knowledge deficits.