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Funding Support (Grant) Information in MEDLINE/PubMed

Articles cited in MEDLINE/PubMed receive funding from a variety of sources. Article citations are tagged with funding support information. The chart below shows the number of articles funded per year for various funding support categories. Click on the first column category name to run the search in PubMed; in the searches, [gr] = Grant Number; [pt] = Publication Type; and [dp] = date of publication.

Funding Support for Articles Cited in MEDLINE/PubMed

Funding Support CategoryTotal Number of Articles*Articles Published in 2015**Articles Published in 2014Articles Published in 2013Articles Published in 2012Articles Published in 2011Articles Published in 2010Articles Published in 2009Articles Published in 2008Articles Published in 2007
Public Health Service (PHS) Support 2,507,601 126,879 135,460 136,493 131,796 128,349 119,447 111,125 105,455 96,841
PHS Support in PMC (PubMed Central)*** 951,868 62,921 113,594 117,782 113,311 109,172 100,777 91,470 72,794 39,984
Percentage of PHS Supported Articles in PMC 38% 50% 84% 86% 86% 85% 84% 82% 69% 41%
American Recovery and Reinvestment Act Support 1,888 224 371 480 568 343 129 7 0 0
N.I.H. Extramural Support**** 2,172,941 120,003 127,063 128,718 124,092 121,339 113,065 104,654 98,914 91,205
N.I.H. Intramural Support 54,022 5,193 5,839 6,451 6,813 6,663 6,423 6,320 5,978 4,838
NIH Support 2,209,227 123,424 131,745 133,020 128,573 125,497 117,200 108,832 102,943 94,506
NIH Support in PMC 909,808 61,878 112,127 116,456 112,292 108,523 100,389 91,084 72,412 39,672
Percentage of NIH Supported Articles in PMC 41% 50% 85% 88% 87% 86% 86% 84% 70% 42%
Percentage of PHS Support from NIH 88% 97% 97% 98% 98% 98% 98% 98% 98% 98%
United States Government, non-PHS Support 739,622 37,151 40,073 40,581 42,984 39,600 35,354 32,338 31,504 30,429
Non-United States Government Support 6,448,738 468,552 501,345 483,743 451,187 417,142 381,181 345,475 319,840 293,673
*The strategies were revised and rerun for all the publication years. Counts in this table were made on May 25, 2016. Numbers change on a daily basis.
**Numbers from the most recent year may be underestimated due to publication cycles and processing times. One article may be counted twice in different publication years; for example, if it was published online first in one year and then included in a print issue in another year.
***These numbers are not intended to represent compliance with the NIH Public Access policy. Citations for embargoed PubMed Central articles are not included in these counts. The embargo period is a delay, of up to 12 months, from the publication date to when the full-text article is made available in PubMed Central.
****Slightly under-reported because citations also having Intramural NIH support are excluded.

The counts in the chart above only include citations where grant information is readily available.

Searching for Funding Support Information

To search for articles funded by a particular organization, search the Grant field for the institute acronym or the name of the organization found onthis page. For example, the following search will find research funded by the National Center for Emerging and Zoonotic Infectious Diseases:


This search will find research funded by the Wellcome Trust:

"Wellcome Trust"[gr]

This search will find research funded by the National Cancer Institute:

(NIH [gr] OR Research Support, N.I.H., Extramural [pt] OR Research Support, N.I.H., Intramural [pt]) AND nci [gr]

For help with more specific funding support search strategies, contact NLM.

Background Information

The National Library of Medicine (NLM) tracks funding information using two data elements: Grant Number and Publication Type.

Grant Number [gr]

  1. Since 1981, NLM has included research grant numbers or contract numbers or both that designate financial support by any agency of the United States Public Health Service (PHS) which also includes the National Institutes of Health (NIH). The numbers are carried in the NLM journal citation as published in the literature with no standardization except for the prefix portion where the number zero (not the letter O) and the number one (not the letter l) should be present, for example: R01, not ROl. A computer algorithm scans the grant number to isolate the 2-letter grant code and then adds the agency/instituted acronym to the citation. The expanded data are only as dependable as the original source string; some mislabeling of the supporting institution may occur. Initially, only up to three grant numbers were included; that limitation was lifted in 2000.
  2. Since 2006, NLM has added grant information derived from PMC and PubMed My NCBI as result of the NIH Public Access Policy. As a result, grant data may now exist on citations to articles published prior to 1981. The corresponding PT value (see below), however, is not added to the citation when the grant element comes from PMC or PubMed My NCBI association.

Publication Type [pt]

The Medical Subject Headings (MeSH®), which is used by the National Library of Medicine® (NLM®) to describe the content of journal articles for MEDLINE®, includes Publication Types to identify financial support of the research that resulted in the published papers when that support is mentioned in the articles:

Research Support, Non-U.S. Gov't (since 1975)
Research Support, American Recovery & Reinvestment Act (since 2010)
Research Support, U.S. Gov't, Non-P.H.S. (since 1975)
Research Support, U.S. Gov't, P.H.S. (since 1975)
Research Support, N.I.H., Extramural (since 2005)
Research Support, N.I.H., Intramural (since 2005)

Total Citation Counts

For comparison purposes, the overall citation counts in PubMed as of November 17, 2015 were:

Citation Status

Total Citations





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