The AMA's CPT® Professional is the official AMA book with CPT® codes, descriptions, and their guidelines for use. It is approved for use with AAPC certification exams.
AAPC's Procedural Coding Expert also contains the official AMA CPT® codes and descriptions (see sample pages), but omits AMA's guidelines (as no one but the AMA is allowed to publish them) and therefore is not approved for use with AAPC certification exams. However, it does contain CMS's rules and guidelines, and several other features not included in AMA CPT® Professional (view comparison table). For many working in the industry, the Procedural Coding Expert is an excellent supplement, if not a replacement for the AMA's CPT® Professional.