"As of today, 50 U.S. service members have been diagnosed with TBI [traumatic brain injury]," Defense Department spokesman Lt. Col. Thomas Campbell said in a statement.
The troops were injured on Jan. 8 after Iran fired missiles on U.S. and coalition forces at the Al-Assad Air Base in Iraq following the death of Iranian Quds Force Gen. Qassem Soleimani.
Initial estimates put the number of troops who suffered concussions at 34. Fifteen of the 16 newly diagnosed troops have returned back to duty. Eighteen service members have been transported to Germany for further evaluation and treatment, the Pentagon said.
Campbell said that the numbers were a "snapshot in time" and could change.
The updated numbers come after President Trump downplayed injuries sustained by service members in the attack.
"I don’t consider them very serious injuries relative to other injuries that I’ve seen,” Trump told a reporter in Switzerland last week where he attended the World Economic Forum in Davos. “I’ve seen what Iran has done with their roadside bombs to our troops.”