The group split in 2010 following a reported falling out between Trace Cyrus and bandmate Mason Musso, but now the duo has reconciled.
Cyrus tells Billboard.com, "After over four years of being apart, fans - and even myself - thought this would never happen.
"I'm extremely excited to be making amazing music with Mason as Metro Station again. We started this band together and it only feels right we finish what we started."
The group will release a new Ep later this year (14) and a tour will begin in Salt Lake City, Utah in October (14).