Civil commitment remains probably the most controversial intervention in mental health. Academic interest in the matter appears to have peaked during the 1970s and 1980s, public interest similarly waxes and wanes. Current legislative proposals in the U.S. emphasize involuntary outpatient commitment and media-fueled views of firearm violence parallel some calls for increased recourse to civil commitment. Unfortunately, no reliable published estimates exist of the number of individuals in the U.S. who are subject to 72-hour involuntary psychiatric holds or longer civil commitment. It appears that that no source attempts to collect anything like complete data or produce an estimate. This presentation first reviews the few existing previous estimates and then examines the available data sources on this subject — including individual State Departments of Health or Mental Health, the Centers for Medicaid and Medicare Services, and the Department of Justice’s National Instant Criminal Background Check System — and their extraordinary limitations. Reasons for the dearth of figures on this most controversial and restrictive intervention in mental health are suggested.