Tenn. Code Ann. § 58-1-220: General officers - Tenure

No general officer of the line and no air guard general officer, unless the officer be the adjutant general, deputy adjutant general, or an assistant adjutant general army and an assistant adjutant general air, shall serve more than three (3) years as a federally recognized general officer. Should a general officer of the line or an air guard general officer of the line hold the rank of major general or occupy a vacancy designated to be held by a major general, such general officer shall, at the discretion of the adjutant general, be allowed to serve for two (2) additional years from the date such general officer is federally recognized as a major general.