A "military hop," officially known as Space-Available (Space-A) Travel, is a unique benefit reserved for specific categories of people associated with the U.S. Department of Defense. Eligible travelers include Active Duty service members (and their dependents), Military Retirees who served at least 20 years, and certain members of the National Guard and Reserves. Additionally, 100% disabled veterans and certain survivors of deceased service members are eligible. Eligibility is divided into six "Categories," which determine priority. Category 1 includes emergency leave, while Category 6—the lowest priority—includes retirees and veterans. In 2026, Space-A travel remains a popular way for the military community to fly globally for a very low cost (often just a small segment fee or tax). However, because these flights are primary for moving cargo and troops, a "hop" is never guaranteed; if the mission requires the seats, Space-A passengers are the first to be removed. Travelers must have a valid military ID and be prepared for significant delays, as flight schedules are subject to change without notice. It is essentially "budget travel" for those with high flexibility and a valid military affiliation.