Medical Subject Headings
Download of any of the full data files requires acceptance of the memorandum of understanding.
- Download NLM Conversion Specifications (pdf format). This is the most current version. References to form, language, and geographic qualifiers should be ignored.
- The NLM Conversion Specifications are to be used in conjunction with another document, USMARC Specifications for Record Structure, Character Sets, and Exchange Media for sale by the Cataloging Distribution Service, Library of Congress.
MeSH/MARC files available to download
If MeSH data change in the middle of the year, a monthly full file and change file with these changes will be made available. Note that these monthly change files will include only changes made during that month - the changes are not cumulative. Mid-year change files that are available are indicated below.
- Sample file contains 41 descriptor records,83 qualifier records, and 869 descriptor/qualifier combinations, for a total of 993 records. Download sample file [318KB]
- Label file provides size and other statistics for the sample file.
- Update-only file contains new and modified terms with 1,471 descriptor records and 7,214 descriptor/qualifier combinations, for a total of 8,685 records. Download update-only file
- Label file provides size and other statistics for the update file.
- Full file contains all terms with 27,455 descriptor records, 83 qualifier records, and 637,286 records including all descriptor/qualifier combination records. Download full file
- Label file provides size and other statistics for the full file.
- If you have questions concerning the content of MeSH/MARC files or FTP of MeSH/MARC data, please contact:
- Jacque-Lynne Schulman
- Medical Subject Headings
- Telephone: 301-594-2091
- email: firstname.lastname@example.org