Here are some links to sites that can help in the search for mappings between CPT and SNOMED CT. Regardless of who has done the mapping in the EHR system or after the data was captured, it is expected that, on audit, a reasonable cliniciant/terminologist would find the mappings to be clinically and technically appropriate. Please note that ONC and CMS do not endorse any of these as solutions in regards to the correctness of mappings, although one could presume that they are in fact generally reliable and appropriately used in the mapping of concepts across terminologies for clinical purposes. These links are provided only as a helpful guide of examples that can be used if mappings between code systems are needed. The NLM UMLS Metathesaurus exists to provide common representations of concepts. This should not be seen as "a mapping tool" but can be used within a more complicated process to identify concept to concept linkages. See http://www.nlm.nih.gov/research/umls/ and http://www.nlm.nih.gov/research/umls/knowledge_sources/metathesaurus/mapping_projects/index.html Many terminology vendors provide mapping services as a core product within their arsenal of offerings. Again, ONC and CMS do not endorse any vendors but a discussion with any of them would be helpful. One could, if looking for terminology services, Google "healthcare terminology vendors" and work down the list. The AMA also provides commercial CPT mappings: https://commerce.ama-assn.org/store/content/snomed