Me. Rev. Stat. tit. 32, § 12227

Any person who receives from the board a license to practice as a certified public accountant prior to the effective date of this chapter or as provided in this subchapter may be styled and known as a certified public accountant, and no other persons may assume that title or use the abbreviation "CPA" or any other words, letters or figures to indicate that the person using the title is a certified public accountant.