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NLM Classification Updated, August 23, 2018

The NLM Classification, available online at, is updated two times a year.

The 2018 winter version, published January 31, 2018, encompassed changes to the NLM Classification resulting from new and changed 2018 Medical Subject Headings (MeSH) terms as well as additional minor updates to the index and schedule.

The 2018 summer version, published August 23, 2018, encompasses the systematic review of particular schedules and other miscellaneous updates.

For more information about the scope of the 2018 summer edition, see

Contact NLM for further information, questions, or comments.

Since its founding in 1836, the National Library of Medicine has played a pivotal role in translating biomedical research into practice and is a leader in information innovation. As one of the 27 Institutes and Centers at the National Institutes of Health, NLM advances research in biomedical informatics and data science and is the world's largest medical library. Millions of scientists, health professionals and the public use NLM services every day.