California Code, Military and Veterans Code - MVC § 16

An oath authorized or required by Division 2 of this code  1 or the regulations issued thereunder or the statutes or regulations governing the United States Army or United States Navy or United States Air Force or the National Guard or the Air National Guard or active militia may be taken before the following persons who are authorized to administer the same within and without the State, namely: all officers and persons authorized to administer oaths by the 136th Article of the Uniform Code of Military Justice  2 adopted by Section 102 as part of this code, the Adjutant General, the Assistant Adjutant General, the administrative officer in the Office of the Adjutant General, officers of the National Guard when such oath is authorized or required in a matter pertaining to the National Guard, and officers of the Naval Militia when such oath is authorized or required in a matter pertaining to the Naval Militia, except officers of both land and naval forces on the reserve and retired list while unassigned to duty, or by any other officer authorized to administer oaths under the laws of this State. No charge shall be made for the same.

In other cases where an oath is required by this code, the same may be administered by persons authorized to do so by law.