Cornelius Tucker, Jr., seeks to appeal an order of the magistrate judge finding *572 Tucker competent to stand trial for mailing threatening communications, in violation of 18 U.S.C.A. § 876 (West 2000 & Supp. 2004). We dismiss the appeal for lack of jurisdiction because the order is not appealable. This court may exercise jurisdiction only over final orders, 28 U.S.C. § 1291 (2000), and certain interlocutory and collateral orders. 28 U.S.C. § 1292 (2000); Cohen v. Beneficial Indus. Loan Corp., 337 U.S. 541, 69 S.Ct. 1221, 93 L.Ed. 1528 (1949). Piecemeal or interlocutory appeals are disfavored in the federal courts, especially in criminal cases. United States v. MacDonald, 435 U.S. 850, 853-54, 98 S.Ct. 1547, 56 L.Ed.2d 18 (1978). As the order Tucker seeks to appeal is neither a final order nor an appeal-able interlocutory or collateral order, we deny his motion to dismiss counsel and dismiss the appeal for lack of jurisdiction. We dispense with oral argument because the facts and legal contentions are adequate presented in the materials before the court and argument would not aid the decisional process.

DISMISSED