What altitude do the US Air Force and NASA officially use as the cutoff for awarding astronaut wings?

50 miles (approximately 80.5 kilometers)

A significant divergence exists between the international standard and the definition used by key United States agencies, namely NASA and the US Air Force. These organizations historically utilize a lower threshold of 50 miles above mean sea level, which converts to approximately 80.5 kilometers, as the official point at which an individual is deemed to have achieved astronaut status and qualifies for astronaut wings. This difference of about 20 kilometers creates ambiguity; a person flying to 90 kilometers, for example, would be considered an astronaut by US standards but might not qualify under the FAI's 100 km rule. This split definition often influences decisions made by commercial spaceflight operators who seek to certify their passengers according to the US framework, even if they do not reach the higher international boundary.