If an invitation for a 24-month tour extension is extended by the Command and accepted by the employee, the employee and authorized dependents is authorized a round-trip to home of record. Approximately one year prior to the end of the initial 36-month tour of duty, SRF-JRMC will decide whether to offer the employee an extension. If an additional 24 months is offered and the employee accepts, he/she is eligible for Renewal Agreement Travel (RAT). The employee's command pays for this round-trip travel for employees and any authorized dependents. The sponsor is authorized per diem while in a travel status, but dependents are not.

Please see Defense Finance and Accounting Service RAT for more information

http://www.dfas.mil/civilianemployees/civrelo/renewalagreement.html