Hi,
Do you have a CPT book? There is a section on psychiatry. But there are only a few codes that you need in addition to the Psychotherapy codes for psychologists (90801, 90806). Psychiatrists can use the 90801 and the 90806, but they also use 90862 for medication management (with minimal medical psychotherapy) . They can also bill E&M codes (99201-99205) if they do a medical evaluation. There are a few other odd codes they can use for testing and other things.
Good luck, I hope this info is helpful.
Michele