Experts and consultants or organizations thereof may as authorized by section 3109 of title 5 be employed for the performance of functions under this chapter, and individuals so employed may be compensated at rates not in excess of the daily equivalent of the highest rate which may be paid to an employee under the General Schedule established by section 5332 of title 5, and while away from their homes or regular places of business, they may be paid actual travel expenses and per diem in lieu of subsistence at the applicable rate prescribed in the standardized Government travel regulations, as amended from time to time. Contracts for such employment with such organizations, employment of personnel as experts and consultants, not to exceed ten in number, contracts for such employment of retired military personnel with specialized research and development experience, not to exceed ten in number, and contracts for such employment of retired military personnel with specialized experience of a broad politico-military nature, not to exceed five in number, may be renewed annually.

Service of an individual as an expert or consultant under subsection (a) of this section shall not be considered as employment or holding of office or position bringing such individual within the provisions of section 3323(a) of title 5.

Persons of outstanding experience and ability may be employed without compensation by any agency of the United States Government for the performance of functions under this chapter in accordance with the provisions of section 4560(b) of title 50, and regulations issued thereunder.