Which type of travelers are not subject to the Joint Travel Regulations (JTR) while on official travel?

Contractor employees are not subject to the Joint Travel Regulations (JTR) while on official travel because the JTR is primarily designed for federal employees, including military personnel and government employees. The regulations provide guidelines on per diem, travel expenses, and reimbursement procedures specific to those under government employment or active duty service. Contractor employees, while working on government contracts, follow different regulations and policies that are established by their employers or the contracts they are operating under. This distinction is essential as it emphasizes the difference in treatment and travel reimbursements between government and contractor personnel.