Me. Rev. Stat. tit. 32, § 4176

The department, upon application therefor, may issue a certificate, without examination, in a comparable classification, to any person who holds a certificate in any state, territory or possession of the United States or any country if the requirements for certification of operators under which the person's certificate was issued do not conflict with this chapter and are of a standard not lower than that specified by rules adopted under this chapter. The issuance of a certificate without examination does not exempt a person from any other requirement of an operator or an operator in responsible charge aside from the examination requirement. A person so certified is subject to disciplinary action under section 4175‑A.