We have published median and mean direct cost award amounts for R01 grants, but these statistical aggregates can mask variations present in our grant portfolio. In this analysis, we illuminate two major differences in R01 award size distributions: those between single-principal investigator (PI) and multiple-PI (MPI) grants and those between new and competing renewal grants. It is worth noting that the numbers are per award values rather than the total NIGMS support provided to investigators and that award size can also be influenced by NIH-wide policies and NIGMS-specific policies that promote the consideration of multiple factors in making funding decisions.
The first major distinction in NIGMS R01s exists between single-PI and MPI awards. NIH has allowed applications that identify more than one PI since Fiscal Year 2007. Many MPI applications request, and receive, larger amounts of funding than do typical single-PI applications. As shown in Figure 1, single-PI awards have a size peak in the range of $175,000-200,000 in direct costs (funds typically directly associated with the research project rather than overhead costs), while MPI awards tend to have larger budgets and a broader size distribution. MPI awards are, on average, approximately 25% larger for each additional PI (data not shown).