Each quick-reference guideline is reviewed and approved by the authoring organization prior to publishing. In many cases the chairs/co-chairs of the original guideline serve as the expert reviewers. You can always rest assured that, even though the guidelines are much shorter than the original (full-text) version, no important information is ever omitted or changed in any way/shape/form. As far as the codes, they are provided directly by the experts at AMA (for CPT) and AAPC (for ICD 10). So this product has the backing and endorsement of some of the most credible and well-respected organizations in healthcare.