PurposeTelephone disclosure of genetic test results can improve access to services. To date, studies of its impact have focused on return of Mendelian risk information, principally hereditary cancer syndromes.MethodsIn a multisite trial of Alzheimer disease genetic risk disclosure, asymptomatic adults were randomized to receive test results in person or via telephone. Primary analyses examined patient outcomes 12 months after disclosure.ResultsData from 257 participants showed that telephone disclosure occurred 7.4 days sooner and was 30% shorter, on average, than in-person disclosure (both P < 0.001). Anxiety and depression scores were well below cutoffs for clinical concern across protocols. Comparing telephone and in-person disclosure protocols, 99% confidence intervals of mean differences were within noninferiority margins on scales assessing anxiety, depression, and test-related distress, but inconclusive about positive impact. No differences were observed on measures of recall and subjective impact. Subanalyses supported noninferiority on all outcomes among apolipoprotein E (APOE) ɛ4-negative participants. Subanalyses were inconclusive for APOE ɛ4-positive participants, although mean anxiety and depression scores were still well below cutoffs for clinical concern.ConclusionTelephone disclosure of APOE results and risk for Alzheimer disease is generally safe and helps providers meet demands for services, even when results identify an increased risk for disease.