Mass. Gen. Laws ch. 152 § 45
After an employee has received an injury, and from time to time thereafter during the continuance of his disability he shall, if requested by the insurer or insured, submit to an examination by a registered physician, furnished and paid for by the insurer or the insured. The employee may have a physician provided and paid for by himself present at the examination. If a physician provided by the employee is not present at the examination, it shall be the duty of the insurer to file with the division a copy of the report of its examining physician or physicians if and when such report is to be used as the basis of any order by the division. If the employee refuses to submit to the examination or in any way obstructs it, his right to compensation shall be suspended, and his compensation during the period of suspension may be forfeited. The employee's right to compensation shall also be suspended during any period the employee refuses the insurer's written request that the employee be evaluated by a vocational rehabilitation specialist within the department. This written request may occur only once every six months.
If the injured employee, at the request of the insurer or the division undergoes medical examination or treatment such employee shall be reimbursed by the insurer for reasonable travel expense incidental thereto and for any loss of wages as a result thereof in like manner as though he were disabled under the provisions of this chapter. Such payments shall not be construed as an admission of liability by the insurer in those cases where the liability has not been assumed by it. If the amount of such reimbursement is not agreed upon by the parties, it may be determined by a hearing as provided under section twelve.
Mass. Gen. Laws ch. 152, § 45