Thank you all for your answers!
Thomas, while your thoughts about skin check being part of the PCP's annual exam probably parallel that of CMS and the other payers, I do not agree with it from a clinical perspective. First, I don't believe that most PCPs perform a full skin exam during the annual examination. Second, even if they were to do so, they don't have the experience or expertise to do this effectively; they might end up doing unnecessary biopsies of lesions that an experienced dermatologist can tell at a glance are benign, and possibly fail to recognize signs of suspicion in other lesions. Skin exam is not something that can be done "by the book"; it takes an experienced and discerning eye that only a specialist should be expected to possess.
Sorry for the rant; after almost a decade of working with dermatologists, I guess I've gotten opinionated!