A taxonomy code is a unique 10-character code that identifies a healthcare providers classification and specialization. It is used to self-identify a providers specialty based on which taxonomy code best matches their specialty. The Health Care Provider Taxonomy code set is a collection of unique alphanumeric codes, ten characters in length, that is structured into three distinct levels: provider grouping, classification, and area of specialization. Providers must select a taxonomy code when completing their application for a National Provider Identifier (NPI) . Taxonomy codes are required on NPI applications to designate provider type or specialty. They are also used to select the correct record in the HIPAA standard transactions and are required for Medicaid claims for BlueSalud/BlueSCI. It is important for providers to select the taxonomy code that most closely resembles their specialty to ensure correct payment of claims. To find the taxonomy code that most closely describes a providers type, classification, or specialization, one can use the National Uniform Claim Committee (NUCC) code set list.