J. RANDAL HALL, District Judge.
In the captioned criminal matter, Defendant Joey Leon Greene, Jr. has written the Court a detailed letter outlining his personal circumstances and post-sentencing rehabilitation efforts. On the strength of these matters, Defendant seeks reconsideration of his sentence and even immediate release. With only three exceptions, however, a court may not modify a sentence once it has been imposed. 18 U.S.C. § 3582(c). Under the first exception, a court may entertain a motion filed by the Director of the Bureau of Prisons under certain circumstances. 18 U.S.C. § 3582(c)(1)(A). The second exception references Rule 35 of the Federal Rules of Criminal Procedure for instances when correcting sentence is proper. 18 U.S.C. § 3882(c)(1)(B). Rule 35 allows modification upon an order from an appellate court, upon a motion from the Government, or to correct a computational error within seven days of sentencing. Finally, under the third exception a court may reduce a sentence that was "based on a sentencing range that has subsequently been lowered by the Sentencing Commission pursuant to 28 U.S.C. § 944(o)." 18 U.S.C. § 3582(c) (2) . Defendant's request for a reduction in this case does not fall within any of these exceptions. Accordingly, the Court is without authority to modify the Defendant's sentence as requested. His motion to reduce (doc. 181) is therefore