Background:National Institutes of Health (NIH) funding of orthopaedic surgery departments has historically lagged behind that of other surgical disciplines. In this study, we present an updated analysis of NIH grants awarded to orthopaedic surgery departments at U.S. medical schools and an evaluation of the characteristics of NIH-funded principal investigators (PIs).Methods:The NIH Research Portfolio Online Reporting Tools Expenditures and Results (RePORTER) database was queried for grants awarded to orthopaedic surgery departments in the 2015 to 2021 fiscal years. Funding totals were calculated for 4 categories: award mechanism, awarding institute, recipient institute, and PI. Trends in funding from 2015 to 2021 were determined and compared with the annual NIH budget. Funding awarded to orthopaedic surgery departments was compared with awards received by other surgical specialties in 2021. The characteristics of NIH-funded PIs and co-PIs were evaluated. Funding awarded to orthopaedic surgery departments in 2021 was compared with funding in 2014 as reported in a previous study.Results:In 2021, 287 grants were awarded to 187 PIs at 47 orthopaedic surgery departments for a total of $104,710,841, representing 0.4% of the overall NIH budget. The top 5 departments earned $41,750,321 (39.9%) of the total NIH funding for orthopaedic surgery. From 2015 to 2021, total funding increased by 79.7% (p < 0.001), but the rate of increase was not significantly different from that of the overall annual NIH budget (p = 0.469). In 2021, grants were most commonly awarded via the R01 mechanism (70.0% of total funding), with a median annual award of $397,144 (interquartile range [IQR], $335,017 to $491,248). The majority of grants (70.0%) supported basic science research, followed by translational (12.2%), clinical (9.4%), and educational (8.4%) research. NIH funding did not vary by the gender of the PI (p = 0.505), and the proportion of female PIs was significantly greater in 2021 than in 2014 (33.9% versus 20.5%, p = 0.009). Compared with other surgical departments, orthopaedic surgery departments ranked second-lowest in terms of the total NIH funding received in 2021.Conclusions:NIH funding to orthopaedic surgery departments continues to be limited and lags behind that of other surgical subspecialties, which may create challenges in addressing the rising burden of musculoskeletal disease in the U.S. These findings highlight the importance of efforts to identify barriers to grant procurement in orthopaedic surgery.