Background: The objective of this study was to present 12-month and lifetime prevalence, correlates, comorbidity, treatment and disability of DSM-5 bipolar I disorder. Methods: Nationally representative U.S. adult sample (N = 36,309), the 2012-2013 National Epidemiologic Survey on Alcohol and Related Conditions - III. Results: Prevalences of 12-month and lifetime DSM-5 bipolar I disorder were 1.5% and 2.1% and did not differ between men (1.6% and 2.2%) and women (1.5% and 2.0%). Prevalences of bipolar I disorder were greater among Native Americans, and lower among Blacks, Hispanics and Asians/Pacific Islanders than whites. Rates were also lower among younger than older individuals, those previously married than currently married and with lower education and income relative to higher education and income. Bipolar I disorder was more strongly related to borderline and schizotypal personality disorders (adjusted odds ratios (AORS) = 2.2-4.7)), than to anxiety disorders (AORs = 1.3-2.9), and substance use disorders (AORs = 1.3-2.1) overall and among men and women. Quality of life was lower among individuals with bipolar I disorder relative to those without the disorder. Treatment rates among individuals with bipolar I disorder were low in the total sample (46%, SE = 2.63), among men (36.7%, SE = 3.82) and among women (55.8%, SE = 3.32). Conclusions: Bipolar I disorder continues to be common disabling and highly comorbid disorder among men and women, contributing substantially to low quality of life and burden of disease in our society. (C) 2016 Published by Elsevier Ltd.