Congress's contempt power is the means by which Congress responds to certain acts that in its view obstruct the legislative process. Contempt may be used either to coerce compliance, to punish the contemnor, and/or to remove the obstruction. Although arguably any action that directly obstructs the effort of Congress to exercise its constitutional powers may constitute a contempt, in recent times the contempt power has most often been employed in response to non-compliance with a duly issued congressional subpoena-whether in the form of a refusal to appear before a committee for purposes of providing testimony, or a refusal to produce requested documents. Congress has three formal methods by which it can combat non-compliance with a duly issued subpoena. Each of these methods invokes the authority of a separate branch of government. First, the long dormant inherent contempt power permits Congress to rely on its own constitutional authority to detain and imprison a contemnor until the individual complies with congressional demands. Second, the criminal contempt statute permits Congress to certify a contempt citation to the executive branch for the criminal prosecution of the contemnor. Finally, Congress may rely on the judicial branch to enforce a congressional subpoena. Under this procedure, Congress may seek a civil judgment from a federal court declaring that the individual in question is legally obligated to comply with the congressional subpoena. A number of obstacles face Congress in any attempt to enforce a subpoena issued against an executive branch official. Although the courts have reaffirmed Congress's constitutional authority to issue and enforce subpoenas, efforts to punish an executive branch official for non-compliance with a subpoena through criminal contempt will likely prove unavailing in many, if not most, circumstances. Where the official refuses to disclose information pursuant to the President's decision that such information is protected under executive privilege, past practice suggests that the Department of Justice (DOJ) will not pursue a prosecution for criminal contempt. In addition, although it appears that Congress may be able to enforce its own subpoenas through a declaratory civil action, relying on this mechanism to enforce a subpoena directed at an executive official may prove an inadequate means of protecting congressional prerogatives due to the time required to achieve a final, enforceable ruling in the case. Although subject to practical limitations, Congress retains the ability to exercise its own constitutionally based authorities to enforce a subpoena through inherent contempt. This report examines the source of the contempt power, reviews the historical development of the early case law, outlines the statutory and common law basis for Congress's contempt power, and analyzes the procedures associated with inherent contempt, criminal contempt, and the civil enforcement of subpoenas. The report also includes a detailed discussion of two recent information access disputes that led to the approval of contempt citations in the House against then-White House Chief of Staff Joshua Bolten and former White House Counsel Harriet Miers, as well as Attorney General Eric Holder. Finally, the report discusses both non-constitutional and constitutionally based limitations on the contempt power.