5 U.S. Code § 5703

5.U.S. Code § 5703 is about Per diem, travel, and transportation expenses; experts and consultants; individuals serving without pay. It is under Subchapter I (Travel And Subsistence Expenses; Mileage Allowances) of Chapter 57 (Travel, Transportation, And Subsistence) of Subpart D (Pay and Allowances) of Part III (Employees) of Title 5 (Government Organizations and Employees) of the Code.

An employee serving intermittently in the Government service as an expert or consultant and paid on a daily when-actually-employed basis, or serving without pay or at $1 a year, may be allowed travel or transportation expenses, under this subchapter, while away from his home or regular place of business and at the place of employment or service.