How many gregor the overlander books are there?

There are five books in the *Gregor the Overlander* series by Suzanne Collins:

1. Gregor the Overlander (2003)

2. Gregor and the Prophecy of Bane (2005)

3. Gregor and the Curse of the Warmbloods (2007)

4. Gregor and the Marks of Secret (2009)

5. Gregor and the Code of Claw (2011)