Clinical functional analysis (CFA) lays the groundwork for many diagnostic and therapeutic measures for craniomandibular dysfunction (CMD). Hence, Code 8000 of the German Dental Fee Schedule (GOZ) is central to billing for such functional analysis services. However, the principles for evidence-based practice of functional diagnostics have evolved substantially, which is rarely more evident than in GOZ Code 8000: 'Clinical functional analysis, including documentation.' The mismatch between the fee schedule specifications and current practice guidelines becomes particularly obvious when reading the procedural code description for CFA, which was taken from the former GOZ 1988 and adopted in the new and revised GOZ 2012, without updates or changes. Code 8000 states: “The service under no. 8000 also includes the following dental services: prophylactic, prosthetic, periodontal and occlusal examination, functional diagnosis of X-rays of the skull and cervical spine, and clinical reaction tests (such as a resiliency test and provocation test).” The German Dentistry Act requires dentists in Germany to practice dentistry according to current scientific evidence. However, it is difficult to reconcile best practice according to current scientific evidence with the outdated provisions of the GOZ. This article describes this problem in detail, based on the example of GOZ Code 8000. In the case of CFA, it is important to distinguish the exact scope of services included in GOZ Code 8000, since the field of dental functional diagnostics has undergone enormous scientific development and diversification in recent decades, yielding new and distinct services that must be billed separately. Palabras clave: clinical functional analysis (CFA), craniomandibular dysfunction (CMD), temporomandibular disorders (TMD), fee schedule, German Dental Fee Schedule (GOZ)