At the same time, generalizing across the entire RBRVS is problematic since not all procedural and surgical services are alike. Many physicians providing cognitive services may support existing fees for high stakes and highly complex services. Cognitive physicians are likely to bristle at the reimbursement levels for less intensive and lower-risk services; these kinds of services usually decline in difficulty as familiarity increases. Unlike evaluation and management services, the times initially estimated by the Relative Value Scale Update Committee are likely to increasingly diverge from actual times. As Dr Mathers suggests, the valuation of colonoscopies is a prime example; likewise, endoscopy services and less complicated or low-risk surgeries are sometimes given as examples. Among noncognitive specialists, income from just a few highly valued services such as these significantly enhances practice revenue. Specialty society representatives refer to these kinds of codes that provide a good basis for their revenue as “bread and butter” codes.