After serving as Tenmon hakase, Seimei went beyond Onmyoryo, successively holding various government posts such as Kazue no gon no suke, Daizen taifu, Sakyo no gon no daifu and the magistrate of the powerful Harima Province and climbed to 'Jushiinoge (Junior Fourth Rank, Lower Grade).'
天文博士を勤めた後には陰陽寮を超えて主計権助・大膳大夫・左京権大夫・大国である播磨守などの官職を歴任して「従四位下」まで昇進した。