The NSF, "as a general policy", will fund only up to two months' salary for senior personnel on its grants, which includes PIs and another category of, roughly, "people who smell like faculty." This rule doesn't apply for non-senior personnel. Also, while I haven't found this caveat on the NSF's website, I have seen on several university research offices' sites that the rule doesn't apply to "soft-money" people, i.e. those whose salaries are normally fully funded by grants.

I work at a private research institute (non-profit) whose income is entirely from grants, and thus we're all soft money here. I'm applying to an NSF grant as a PI and, while it seems like the two-ninths rule is probably binding on me as a PI at least in principle, it's not completely clear to me to what extent asking for more than two months' salary, say up to four or five, would be a big negative on our application. Does anybody have any experience with this? It's quite confusing especially because "under normal rebudgeting authority" it looks as if I would be fully within NSF rules to budget for salary for a colleague here but then rebudget to spend that money on my own salary after the award. Enclosing the relevant NSF policies below.

As a general policy, NSF limits the salary compensation requested in the proposal budget for senior personnel to no more than two months of their regular salary in any one year. (See Exhibit II-3 for the definitions of Senior Personnel.) It is the organization’s responsibility to define and consistently apply the term “year”, and to specify this definition in the budget justification. This limit includes salary compensation received from all NSF-funded grants. This effort must be documented in accordance with 2 CFR §200, Subpart E, including 2 CFR §200.430(i). If anticipated, any compensation for such personnel in excess of two months must be disclosed in the proposal budget, justified in the budget justification, and must be specifically approved by NSF in the award notice budget.[14]

Under normal rebudgeting authority, as described in Chapters VII and X, a recipient can internally approve an increase or decrease in person months devoted to the project after an award is made, even if doing so results in salary support for senior personnel exceeding the two-month salary policy. No prior approval from NSF is necessary unless the rebudgeting would cause the objectives or scope of the project to change. NSF prior approval is necessary if the objectives or scope of the project change.

  • 7
    You can always ask your program officer for clarification.
    – Bryan Krause
    Commented Apr 2 at 22:13
  • 5
    And your institutions grant administrators…
    – Jon Custer
    Commented Apr 3 at 1:51
  • @BryanKrause Yes, thanks; I did that and it helped somewhat but as I expected the answer I got was a bit vague. The answer here has substantial advantages in concrete experience which is just what I was hoping for. Commented Apr 3 at 23:12
  • @JonCuster My institution’s grant administrators! You mean 10% of my CEO and 20% of my accountant, I guess :) There are 11 people at my institution of whom 2.5 do non-research. It’s a bit of a different world from the university. Commented Apr 3 at 23:13

2 Answers 2


research admin here. This is a point of confusion with NSF, and has been for at least about 10 years. It's the proposal / post-award divide. It also depends on your directorate on how this will go. I mostly work with folks in CISE, and those program officers are aggressive at the time of award that you can not charge above 2 months total -- they make you promise before accepting the award. My institution does not see how that is a valid way of handling such a term and condition.

At any rate, for someone in your case, it all comes down to the proposal. You need to put the effort amount in the proposal and then justify it. If it's approved, then it's approved. Please note that if you are senior personnel, this does become committed effort.

Here's an example of something I submitted some years ago, but should still be valid:

Principal Investigator: Salary is requested for PI [Name]: 4 months in year 1, 6 months in year 2, 4 months in year 3, and 4 months in year 4, with one month being equal to 1/12 of his salary. The PI's appointment is a research-only appointment with no salary guaranteed by the University. In accordance with historical University salary practices, this amount is increased by 3% at the start of each new fiscal year (July 1). The PI will be responsible for the cohesion of the entire project. With his expertise in [X TOPIC], his leadership in the research project is essential. He will also mentor the postdocs and graduate students and lead in the design, implementation and reporting on the proposed research.

If they approve at such levels, they know that you asked for more effort up front. If you want to mention the appointment setup you can, just consult your research administrator for what is considered the appropriate level of disclosure. My office does "1/9" or "1/12" to disclose this type of PI, and we sometimes make the statement as above to state they have no guaranteed salary. The PAPPG language is trying to say that NSF funding is not supposed to be a way of funding professors that should ordinarily be paid by their institutions--they don't want NSF funding to be the reason faculty have their jobs--it's incidental funding on top of their research/academic appointments.

As for the post-award component, let's say you submit the above request asking for 4 months or 6 months -- this is the catch. You can't rebudget after the approved budget to go up to 8 months without approval. So if you only ask for one month, the PAPPG says, if you need to do a rebudget, you can now charge 2 months on that project without approval. Where my folks get caught is having say, 3 projects, proposed with one month each. At the time of awarding the third grant, the NSF Program Officer sweeps in and says, "please agree that you won't charge more than 2 months across all projects". This is where I feel we cannot reasonably charge 3 months despite the language in the PAPPG, but it's really not a fair way of doing business. In such a case, it's unclear what effort is committed on each project then. My institution allows us to cost share pretty generously, so that's what we end up doing. In smaller institutions, you take a funding cut in salary to comply.

All this to say that this is very confusing and individual institutions may take a hardline stance about the 2 month rule to avoid any potential audit risk. Find your assigned research administrator and ask what their rules are. If they have none -- feel free to use the language I give above in your budget justification.

You also sound like your institution is not part of FDP--so I would clarify with your post-award folks on what normal rebudget authority looks like for your institution. It varies based on your institution's status with FDP. These institutions subject themselves to higher auditing standards to get prior approvals with the government waived. Such a matrix is maintained on NSF's website.

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    Thanks very much! The direct experience of how different POs can vary is invaluable. The POs of the current program (or at least, whoever’s running the joint program email account) seem to think of the two-ninths rule as just a suggestion, but who knows what the next PO might think… Commented Apr 3 at 23:18

I've charged more than two months salary in a year to my NSF grants. The context is that I'm a mathematics faculty member, but my sponsored projects aim to advance the cyberinfrastructure of math and math education research and practice.

In particular, the two month rule seems to be intended to prevent NSF from paying faculty to do what their institution is already paying them to do: do basic research in their field. In my situation, I was able to argue in my proposal and budget justification that my proposed work was outside the scope of basic research in my field.

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