The U.S. Postal Service still plans to find a new location for the Richland post office at 815 Jadwin Ave.
Spokesman Ernie Swanson said the change is expected to save money but "nothing concrete" has been found.
"We've had facilities people looking at possible sites, but nothing has happened," he said.
The post office has no timetable for moving, but "the sooner we can get out of our lease the better," Swanson said.
Officials say the facility is too large now that mail carrier operations were moved to the West Richland post office.
The move of the Richland post office is one of several that the postal service proposed in the Tri-Cities in an attempt to cut costs. It moved its mail handling operations from Pasco to Spokane last summer and also announced it may close the downtown Pasco post office.