Skip Navigation Bar

Unified Medical Language System® (UMLS®)

2012AA Metathesaurus HCPCS Hierarchical Terms Source Information


 (skip to: notes  samples)

Term Type Description Count (MRCONSO.RRF)
HT Hierarchical term 343


  • A term type indicates the role an atom plays in its source
  • An atom is the smallest unit of naming in a source; that is, a specific string with specific code values and identifiers from a specific source.
  • Every atom has a separate row in MRCONSO.RRF. Every atom is assigned a term type.
  • Term types are assigned based on source documentation or NLM understanding of the source.
  • Sample data are provided for every term type in the source (see below).
  • See Metathesaurus Documentation for a list of all term type abbreviations and their full names.
  • See Metathesaurus Documentation for a list of sources and their associated term types, listed in default order of precedence.
  • See Section 2.3 of the UMLS Reference Manual for more information on terms and term types in the UMLS Metathesaurus.

Sample Data


  (return to top)
C0851270 A13300085 L1702378 S1919515 MTHU000316 MTHU000316 HCPCS Level I Preferred Terms, Obsolete
C0919279 A13300770 L1776219 S2071440 Level 1: A0000-A9999 Level 1: A0000-A9999 A Codes
C0441134 A13299348 L0774654 S1801343 Level 3: A4300-A4306 Level 3: A4300-A4306 Vascular Catheters
C0812882 A13295817 L1506618 S1801693 Level 3: A4611-A4629 Level 3: A4611-A4629 Supplies for Oxygen and Related Respiratory Equipment
C1971535 A13297257 L0871622 S8012288 Level 3: A4648-A4652 Level 3: A4648-A4652 Miscellaneous Surgical Supplies
C0812886 A13299349 L1506175 S1800433 Level 3: A5051-A5093 Level 3: A5051-A5093 Additional Ostomy Supplies
C0812889 A13297258 L1506551 S1801569 Level 3: A5500-A5513 Level 3: A5500-A5513 Diabetic Shoes, Fitting, and Modifications
C0812894 A13297926 L1506612 S1801682 Level 2: B4034-B4162 Level 2: B4034-B4162 Enteral Formulae and Enteral Medical Supplies
C0812896 A13300772 L1506613 S1801683 Level 2: B9000-B9999 Level 2: B9000-B9999 Enteral and Parenteral Pumps