OBJECTIVE: Several publication databases now index the associated funding agency and grant number metadata with their publication records. Librarians who are familiar with the particulars of these databases can assist investigators and administrators with data gathering for publication summaries and metrics required for renewals of and progress reports for National Institutes of Health (NIH) grants. METHODS: Publication lists were pulled from three main indexers of publication-associated funding information (NIH RePORTER, PubMed, and Web of Science), using iterative search strategies. All discovered variations for the cited grant number of interest were recorded and tested. Publication lists were compared for overall coverage. RESULTS: A total of 986 publications citing the single grant number of interest were returned from the given time frame: 920 were found in PubMed, 860 in NIH RePORTER, and 787 in Web of Science. Web of Science offered the highest percentage of publications that were not found in the other 2 sources (n=63). Analysis of publication funding acknowledgments uncovered 21 variations of the specific NIH award of interest that were used to report funding support. CONCLUSIONS: This study shows that while PubMed returns the most robust list of publications, variations in the format of reported funding support and indexing practices meant no one resource was sufficient to capture all publications that cited a given NIH project grant number. Librarians looking to help build grant-specific publication lists will need to use multiple resources and be aware of the most frequently reported grant variations to identify a comprehensive list of supported publications.