Hearing involving medical issues.

When the hearing involves medical issues, the medical assessment of the claimant’s condition must be made by a medical authority other than the persons who made the original medical determination if the hearing officer or the claimant considers an additional examination necessary. The additional medical assessment shall be limited to one assessment which shall be obtained at agency expense, and, when requested by the claimant, shall be obtained from a medical source satisfactory to the claimant.