Aims To investigate among older adults with DSM-5 alcohol use disorder (AUD) the relevance of (1) baseline DSM-5 AUD severity, (2) age of DSM-5 AUD onset, and (3) the interactions of DSM-5 AUD severity∗treatment condition and age of DSM-5 AUD onset∗treatment condition for the prediction of AUD treatment outcomes. Methods The international multicenter RCT "ELDERLY-Study"compared outpatient motivational enhancement therapy (4 sessions) with outpatient motivational enhancement therapy followed by community reinforcement approach for seniors (8 sessions) in adults aged 60+ with DSM-5 AUD. Baseline and 1-, 3-, and 6-month follow-up data from the German and Danish ELDERLY-sites (n = 544) were used (6-month participation rate: 75.9%). DSM-5 AUD diagnoses were obtained using the Mini International Neuropsychiatric Interview and alcohol use using Form 90. Associations between DSM-5 AUD severity and age of onset and AUD treatment outcomes were investigated using multiple logistic regression and generalized linear models. Results The sample was diverse in AUD severity (severe: 54.9%, moderate: 28.2%, mild: 16.9%) and age of onset (median: 50 years; 12-78 years). Overall, with few exceptions, neither AUD severity, nor age of onset, nor their respective interactions with treatment condition significantly predicted drinking outcomes at the different follow-ups (P ≥ 0.05). Conclusions No indication was found for the need to tailor treatment content according to DSM-5 AUD severity and earlier onset in older adults. © Wolters Kluwer Health, Inc. All rights reserved.