                                                       United States Court of Appeals
                                                                Fifth Circuit
               IN THE UNITED STATES COURT OF APPEALS
                       FOR THE FIFTH CIRCUIT                 F I L E D
                                                              June 24, 2003

                            No. 02-51384                  Charles R. Fulbruge III
                        Conference Calendar                       Clerk



UNITED STATES OF AMERICA,


                                    Plaintiff-Appellee,

versus

JOSE CASTELAN, JR, also known as Jose Carmen Castelan-Carbajal,
also known as Peter Garcia, also known as Jose Catellan,

                                    Defendant-Appellant.

                       --------------------
          Appeal from the United States District Court
               for the Western District of Texas
                   USDC No. A-01-CR-109-ALL-JN
                       --------------------

Before DeMOSS, DENNIS, and PRADO, Circuit Judges.

PER CURIAM:*

     Jose Castelan, federal prisoner # 79424-080, appeals the

district court’s denial of his post-conviction motion for a

reduction of his sentence or downward departure from the

guidelines range based on his cultural assimilation.     Castelan

relies on United States v. Rodriguez-Montelongo, 263 F.3d 429

(5th Cir. 2001), which was issued after he was sentenced and

held for the first time in a published opinion that cultural



     *
        Pursuant to 5TH CIR. R. 47.5, the court has determined
that this opinion should not be published and is not precedent
except under the limited circumstances set forth in 5TH CIR.
R. 47.5.4.
                           No. 02-51384
                                -2-

assimilation is a “permissible basis for downward departure”

under U.S.S.G. § 5K2.0.

     This court has a continuing duty to consider, sua sponte if

necessary, the basis of the district court’s jurisdiction.

Solsona v. Warden, F.C.I., 821 F.2d 1129, 1132 n.2.    The district

court is prohibited from modifying a term of imprisonment once it

has been imposed except in certain limited circumstances.       18

U.S.C. § 3582(c).   Castelan’s post-conviction motion for a

sentence reduction or downward departure does not fall under any

provision of 18 U.S.C. § 3582(c) and, thus, was unauthorized and

without a jurisdictional basis.     See United States v. Early, 27

F.3d 140, 141-42 (5th Cir. 1994).    Although the district court

considered the motion on its merits, it should have denied the

motion for lack of jurisdiction.    See id. at 142.   On that

alternative basis, the district court’s order is

     AFFIRMED.
