Ernestine Brock seeks review of the magistrate judge’s order* affirming the Commissioner’s denial of social security benefits pursuant to 20 C.F.R. § 404.1520(f) (2002). Our review of the record discloses that the Commissioner’s decision is based upon substantial evidence and is without reversible error. In particular, we find that substantial evidence supports a finding that Brock retains the residual functional capacity to perform medium work and, therefore, is able to return to her past relevant work as a certified nursing assistant. Accordingly, we affirm the magistrate judge’s order. Brock v. Barnhart, No. CA-01-2488-JFM (D.Md. Aug. 15, 2002). We dispense with oral argument because the facts and legal contentions are adequately presented in the materials before the court and argument would not aid the decisional process.

AFFIRMED.