Workers’ Compensation Law § 24-a (in part):

4. Only an attorney, or a representative licensed in accordance with rules established by the board pursuant to subdivisions three-b and three-d of section fifty of this chapter, shall appear on behalf of an employer or an insurance carrier regarding a claim for compensation or any benefits under this chapter before the board or any officer, agent or employee of the board assigned to conduct any hearing relative to a claim for compensation or benefits under this chapter. The provisions of this subdivision shall not apply to a designated regular employee of a self-insured employer, or of an insurance carrier appearing on behalf of their employer, but the board may prohibit the appearance of any such employee for cause.