20 C.F.R. § 30.410
Can OWCP require an employee to be examined by another physician?
(a) OWCP sometimes needs a second opinion from a medical specialist. The employee must submit to examination by a qualified physician who conforms to the standards regarding conflicts of interest adopted by OWCP as often and at such times and places as OWCP considers reasonably necessary. Also, OWCP may send a case file for second opinion review to a qualified physician who conforms to the standards regarding conflicts of interest adopted by OWCP where an actual examination is not needed, or where the employee is deceased.
(b) If the initial examination is disrupted by someone accompanying the employee, OWCP will schedule another examination with a different qualified physician who conforms to the standards regarding conflicts of interest adopted by OWCP. The employee will not be entitled to have anyone else present at the subsequent examination unless OWCP decides that exceptional circumstances exist. For example, where a hearing-impaired employee needs an interpreter, the presence of an interpreter would be allowed.
(c) OWCP may administratively close the claim and suspend adjudication of any pending matters if the employee refuses to attend a second opinion examination.