The agency may authorize per diem or actual expense and round-trip transportation expenses for periodic return travel to the employee's home or official station under the following circumstances:

1. (a) The agency requires the employee to return to their official station to perform official business;
2. (b) The agency will realize substantial cost savings by the employee's return home; or
3. (c) Periodic return travel home is justified as part of an extended TDY assignment.