An understudied crucial step in the help-seeking process is making prompt initial contact with a treatment provider after first onset of a mental disorder. To provide data on patterns and predictors of failure and delay in making initial treatment contact after first onset of a mental disorder in the United States from the recently completed National Comorbidity Survey Replication. Nationally representative face-to-face household survey carried out between February 2001 and April 2003. A total of 9282 respondents aged 18 years and older. Lifetime DSM-IV disorders were assessed with the World Mental Health (WMH) Survey Initiative version of the World Health Organization Composite International Diagnostic Interview (WMH-CIDI), a fully structured interview designed to be administered by trained lay interviewers. Information about age of first professional treatment contact for each lifetime DSM-IV/WMH-CIDI disorder assessed in the survey was collected and compared with age at onset of the disorder to study typical duration of delay. Cumulative lifetime probability curves show that the vast majority of people with lifetime disorders eventually make treatment contact, although more so for mood (88.1%-94.2%) disorders than for anxiety (27.3%-95.3%), impulse control (33.9%-51.8%), or substance (52.7%-76.9%) disorders. Delay among those who eventually make treatment contact ranges from 6 to 8 years for mood disorders and 9 to 23 years for anxiety disorders. Failure to make initial treatment contact and delay among those who eventually make treatment contact are both associated with early age of onset, being in an older cohort, and a number of socio-demographic characteristics (male, married, poorly educated, racial/ethnic minority). Failure to make prompt initial treatment contact is a pervasive aspect of unmet need for mental health care in the United States. Interventions to speed initial treatment contact are likely to reduce the burdens and hazards of untreated mental disorder.