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NLM Classification Updated, January 31, 2018

January 30, 2018

Starting in 2017, the NLM Classification, available online at, has moved from an annual spring update to twice-yearly updates. The 2018 winter edition has been issued as of January 31, 2018.

For the winter edition, the 2018 MeSH (Medical Subject Headings) vocabulary was evaluated for inclusion in the Classification index. Several additions and changes were made to the Index and Schedules based on this review.  All main index headings are now linked to the 2018 vocabulary in the MeSH Browser.  Additional minor updates were made to the Index and Schedules.

Summary Statistics for the 2018 Winter Edition

  • 93 index main headings added (86 from 2018 MeSH)
  • 114 index entries modified
  • 2 index headings deleted
  • 8 class numbers added
  • 1 new schedule range header modified
  • 11 class number captions or notes modified
  • No class numbers canceled

The 2018 summer version will be published in mid-to-late August 2018. It will encompass the ongoing systematic review of selected classification schedules and other miscellaneous updates. The PDF version will be updated with all 2018 classification data in the fall.

Contact NLM for further information, or if you have questions or comments.


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Last Reviewed: January 30, 2018