A general officer serving as Attending Physician to the Congress, while so serving, holds the grade of major general. A flag officer serving as Attending Physician to the Congress, while so serving, holds the grade of rear admiral (upper half).
Structure US Code
Subtitle A— General Military Law
CHAPTER 41— SPECIAL APPOINTMENTS, ASSIGNMENTS, DETAILS, AND DUTIES
§ 711. Senior members of Military Staff Committee of United Nations: appointment
§ 711a. American National Red Cross: detail of commissioned officers
§ 712. Foreign governments: detail to assist
§ 713. State Department: assignment or detail as couriers and building inspectors
§ 715. Attending Physician to the Congress: grade
§ 717. Members of the armed forces: participation in international sports