Massachusetts Rules of Professional Conduct Rule 1.12: Former Judge or Arbitrator
(a) Except as stated in paragraph (d), a lawyer shall not represent anyone in connection with a matter in which the lawyer participated personally and substantially as a judge or other adjudicative officer, arbitrator, mediator, or law clerk to such a person, unless all parties to the proceeding consent after consultation.
(b) A lawyer shall not negotiate for 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 as a judge or other adjudicative officer, arbitrator, or mediator. A lawyer serving as a law clerk to a judge, other adjudicative officer, arbitrator or mediator may negotiate for employment with a party or lawyer involved in a matter in which the clerk is participating personally and substantially, but only after the lawyer has notified the judge, other adjudicative officer, arbitrator, or mediator.
(c) If a lawyer is disqualified by paragraph (a), no lawyer in a firm with which that lawyer is associated may knowingly undertake or continue representation in the matter unless:
(1) the disqualified lawyer is 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 tribunal to enable it to ascertain compliance with the provisions of this rule.
(d) An arbitrator selected as a partisan of a party in a multimember arbitration panel is not prohibited from subsequently representing that party.
Adopted June 9, 1997, effective January 1, 1998.
 This Rule generally parallels Rule 1.11. The term "personally and substantially" signifies that a judge who was a member of a multimember court, and thereafter left judicial office to practice law, is not prohibited by these Rules from representing a client in a matter pending in the court, but in which the former judge did not participate. So also the fact that a former judge exercised administrative responsibility in a court does not prevent the former judge from acting as a lawyer in a matter where the judge had previously exercised remote or incidental administrative responsibility that did not affect the merits. Compare the Comment to Rule 1.11. The lawyer should also consider applicable statutes and regulations, e.g. G. L. c. 268A. The term "adjudicative officer" includes such officials as magistrates, referees, special masters, hearing officers and other parajudicial officers. Canon 8A(2) of the Code of Judicial Conduct (S.J.C. Rule 3:09) provides that a retired judge recalled to active service "should not enter an appearance nor accept an appointment to represent any party in any court of the Commonwealth for a period of six months following the date of retirement, resignation or most recent service as a retired judge pursuant to G. L. c. 32, §§ 65E-65G."
 Law clerks who serve before they are admitted to the bar are subject to the limitations stated in Rule 1.12(b).
Corresponding ABA Model Rule. Similar to Model Rule 1.12.
Corresponding Former Massachusetts Rule. See DR 9-101 (A).
Cross-reference: See definition of "consultation" in Rule 9.1 (c).