5 U.S.C. § 5726

(a) For the purpose of subsection (b) of this section, “household goods and personal effects” means such personal property of an employee and his dependents as authorized under regulations prescribed under section 5738 of this title to be transported or stored, including, in emergencies, motor vehicles authorized to be shipped at Government expense. (b) Under regulations prescribed under section 5738 of this title , an employee, including a new appointee and a student trainee to the extent authorized by sections 5722 and 5723 of this title, assigned to a permanent duty station outside the continental United States may be allowed storage expenses and related transportation and other expenses for his household goods and personal effects when— (1) the duty station is one to which he cannot take or at which he is unable to use his household goods and personal effects; or (2) the head of the agency concerned authorizes storage of the household goods and personal effects in the public interest or for reasons of economy. The weight of the household goods and personal effects stored under this subsection, together with the weight of property transported under section 5724(a), may not exceed 18,000 pounds net weight, excluding a motor vehicle described by subsection (a) of this section. (c) Under regulations prescribed under section 5738 of this title , when an employee, including a new appointee and a student trainee to the extent authorized by section 5723 of this title , is assigned to a permanent duty station at an isolated location in the continental United States to which he cannot take or at which he is unable to use his household goods and personal effects because of the absence of residence quarters at the location, nontemporary storage expenses or storage at Government expense in Government-owned facilities (including related transportation and other expenses), whichever is more economical, may be allowed the employee under regulations prescribed by the head of the agency concerned. The weight of property stored under this subsection, together with the weight of property transported under sections 5723(a) and 5724(a) of this title, may not exceed the total maximum weight the employee would be entitled to have moved. The period of nontemporary storage under this subsection may not exceed 3 years.