The label said,
"We notify that actor Lee Joon has been transferred to reservist status as of March 23. From here on, Lee Joon will be carrying out his mandatory military service as a public service worker, per the Military Manpower Administration's order.
Lee Joon, who enlisted back in October of last year in the ROK army, received continued treatment for his panic disorder, which he suffered from since before his enlistment. However, his conditions did not improve, which led to a revision of his status by military regulations, and he was determined unfit to serve as an active duty soldier.
Lee Joon is currently awaiting his summon letter from the MMA. He feels apologetic for not being able to show his healthy side, and he will do his best to fulfill the rest of his mandatory military service once he receives his summons."
Lee Joon revealed that he was diagnosed with panic disorder in February of 2017.