N.Y. Workers' Comp. Law § 19-A
No physician or surgeon in the employ of the board for the purpose of making the examinations required by section nineteen of this chapter, shall, during such employment, be employed by or accept or participate in any fee from any insurance company authorized to write workmen's compensation insurance in this state or from any self-insurer, if such employment or fee relates to a workmen's compensation claim or otherwise except as herein provided. Any physician or surgeon so employed by the board who violates the provisions of this section shall be guilty of a misdemeanor.
The foregoing provisions of this section limiting and restricting the employment of physicians or surgeons in the employ of the board and their acceptance or participation in fees shall not be applicable to medical treatment rendered to their patients who are or may be claimants under article nine of this chapter, provided, however, that any such physician or surgeon shall be disqualified from testifying as a witness in any proceeding before the board or its referees in connection with such claims.
N.Y. Work. Comp. Law § 19-A