The soldier was identified as Staff Sgt. Emil Rivera-Lopez, according to a statement released late Wednesday by the Pentagon. He's still technically listed as duty status whereabouts unknown, or DUSTWUN.
Rivera-Lopez, whose age and unit weren't immediately available, was flying with a crew during a training exercise at the time of the incident.
The helicopter crashed while the crew was training about 20 miles off the southern coast of the country, according to a statement released Friday by U.S. Central Command.
Five troops who were also aboard the chopper were rescued, the release said.
A small team of U.S. Special Forces troops has been on the ground in the midst of Yemen's civil war in support of an operation against the Al Qaida in the Arabian Peninsula (AQAP) terror group.
The Pentagon is working to provide accurate numbers of troops deployed in combat zones, including Iraq and Syria as part of Operation Inherent Resolve, the Pentagon's mission against the Islamic State of Iraq and Syria, or ISIS.
The Force Management Levels for Iraq have been given at about 5,200 while the number for Syria was about 500, though the actual numbers are higher due to troops moving into the country on temporary assignments.