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Annual MEDLINE/PubMed Year-End Processing (YEP): Impact on Searching During Fall 2022

What is YEP? | Indexed Citations | In Process Citations | Searching | Other Resources

Indexed Citations

On December 1, 2022, NLM® expects to temporarily halt the addition of newly-indexed MEDLINE citations to PubMed. Once the end-of-year activities are complete (tentatively targeted for the week of December 5, 2022), the normal MEDLINE/PubMed update schedule will resume, and PubMed will use 2023 vocabulary in the MeSH® translation tables and MeSH database, as well as in the citation data.

In Process Citations

During end-of-year activities, "in process" citations will continue to be added to PubMed. As a result, the number of PubMed records labeled [PubMed - in process] will temporarily increase.


A search limiting terms to fields affected by indexing (e.g., telemedicine [mh]) does not retrieve in process or publisher-supplied records. Therefore, during end-of-year activities when we are not adding recently completed, indexed citations to MEDLINE/PubMed, such searches - including those stored in My NCBI and retrieved through RSS feed stored searches - may not retrieve new records for some weeks. To retrieve new, in process records during this time, you should use searches that do not limit to affected fields (e.g., telemedicine). Note that the search terms are not tagged in this example. In early December, the in process citations that are within the scope of MEDLINE and that have been indexed since December 1, 2022 will be replaced as indexed citations with 2023 MeSH terms, Publication Types, etc. Searches, including My NCBI Stored Searches, containing tagged search terms will then retrieve all applicable MEDLINE records.

Other Resources


Important Dates

  • December 1, 2022: NLM expects to temporarily halt the addition of newly-indexed MEDLINE citations to PubMed.

  • Mid-December 2022: PubMed's MEDLINE citations, translation tables, and the MeSH database will have been updated to reflect 2023 MeSH.

NLM Technical Bulletin Articles

  • Articles in the December issue that address changes MeSH and MEDLINE Indexing.

    Background information is available in previous NLM Technical Bulletin articles.

Related Articles

Last Reviewed: November 8, 2022