American Bar Association Model Rules of Professional Conduct - Rule 1.11. Special Conflicts of Interest for Former and Current Government Officers and Employees
(a) Except as law may otherwise expressly permit, a lawyer who has formerly served as a public officer or employee of the government:
(1) is subject to Rule 1.9(c); and
(2) shall not otherwise represent a client in connection with a matter in which the lawyer participated personally and substantially as a public officer or employee, unless the appropriate government agency gives its informed consent, confirmed in writing, to the representation.
(b) When a lawyer is disqualified from representation under paragraph (a), no lawyer in a firm with which that lawyer is associated may knowingly undertake or continue representation in such a matter unless:
(1) the disqualified lawyer is timely screened from any participation in the matter and is apportioned no part of the fee therefrom; and
(2) written notice is promptly given to the appropriate government agency to enable it to ascertain compliance with the provisions of this rule.
(c) Except as law may otherwise expressly permit, a lawyer having information that the lawyer knows is confidential government information about a person acquired when the lawyer was a public officer or employee, may not represent a private client whose interests are adverse to that person in a matter in which the information could be used to the material disadvantage of that person. As used in this Rule, the term "confidential government information" means information that has been obtained under governmental authority and which, at the time this Rule is applied, the government is prohibited by law from disclosing to the public or has a legal privilege not to disclose and which is not otherwise available to the public. A firm with which that lawyer is associated may undertake or continue representation in the matter only if the disqualified lawyer is timely screened from any participation in the matter and is apportioned no part of the fee therefrom.
(d) Except as law may otherwise expressly permit, a lawyer currently serving as a public officer or employee:
(1) is subject to Rules 1.7 and 1.9; and
(2) shall not:
(i) participate in a matter in which the lawyer participated personally and substantially while in private practice or nongovernmental employment, unless the appropriate government agency gives its informed consent, confirmed in writing; or
(ii) negotiate for private employment with any person who is involved as a party or as lawyer for a party in a matter in which the lawyer is participating personally and substantially, except that a lawyer serving as a law clerk to a judge, other adjudicative officer or arbitrator may negotiate for private employment as permitted by Rule 1.12(b) and subject to the conditions stated in Rule 1.12(b).
(e) As used in this Rule, the term "matter" includes:
(1) any judicial or other proceeding, application, request for a ruling or other determination, contract, claim, controversy, investigation, charge, accusation, arrest or other particular matter involving a specific party or parties, and
(2) any other matter covered by the conflict of interest rules of the appropriate government agency.