The following are known Action Replay Codes for Earthworm Jim on Nintendo Game Boy Advance (GBA).
These codes were also known as GameShark Codes and in most cases will work on both devices.

These codes are for the U.S. version of the game.

Master Code – Must Be On
ec87d1ef
625fd1e6
f93bea05
6afe9ac2

Infinite Health
59fbd52a
bab54211

Infinite Lives
e0f07908
0daf2451

Infinite Ammo
e9d91f93
1a3c6d86

Press AR Button: Slow
dbba3a89
4cb74b94