A grand jury subpoena to an attorney for testimony or documents concerning a client chills the flow of information between lawyer and client essential to a criminal defense. In some cases, this would produce a conflict of interest that warrants the termination of representation. In other cases, the subpoena may be designed to intimidate the attorney, induce cooperation with the government, or deter the assertion of particular defenses. On the other hand, the government has significant interests in issuing such subpoenas, since attorneys are often a useful source of information on clients targeted in grand jury inquiries. Attorneys may also be under investigation for their own misconduct. In various circumstances, attorney testimony or records may be essential to the grand jury's inquiry. To balance the interests involved, the U.S. Justice Department should issue guidelines. First, the guidelines should provide that an attorney will not be subpoenaed if the information is available from another source. Second, it should be shown that the information sought from the attorney is necessary for a legitimate investigative purpose. Third, the subpoena should be authorized by the Attorney General or a designate. Fourth, a subpoena should be limited to materials or testimony required for the investigation. Finally, any theory of waiver for the attorney-client privilege should be cleared through the specified approval process. A total of 233 footnotes are provided.