Just wondering if a 5 yr R01 grant is harder to get approved than a 4 yr R01.... Please advise.
My short answer is:
Furthermore, your default stance should be a 5 year plan at the modular budget limit of $250,000 in direct costs per year.
Long answer after the jump.
Let me deal briefly with the overall cost issue that Tom didn't ask. I'm answering it anyway because I find the two issues to be interrelated in the mind of the newcomer. The worry is, of course, that reviewers will view an application from a newer investigator unfavorably merely because of the size of the award. This is not entirely unbased. There is a belief on the part of some reviewers that junior folks should start with a limited research award, not get too big for their britches, etc. I disagree with this but it is out there.
My basic advice for noobs to the NIH grant system is to ignore this with the original submission and only re-trench for the revision if you get hints of this nonsense from the initial review.
I say this because, first off, I believe that the change from a fully itemized budget to the modular grant program worked. Requiring that grant proposals for under $250,000 in direct costs be specified only in units (modules) of $25,000 and personnel effort (unless the year to year budget changed the number of modules) took the reviewer focus away from the budget. There is almost never any discussion of budget in my experience, save when there is a very large disconnect between the plan and the budget. Hard to get specific, of course, but even with my generous understanding of the difficulties of research, I've occasionally seen proposals where there is at least two person-years of effort that I cannot dream up a legitimate use for. You do need to keep in mind that the NIH proposal is not supposed to be "Hey, let's keep my lab running as it is for another five years, 'kay?". Beyond obvious excess, however, most people don't glance twice at the modular budget.
The duration of support is similarly unremarkable although here I would suggest paying slightly more attention to the nature of your proposal and the experimental timeline. Remember that you will likely be reviewed by at least one person who does the same sorts of studies you are proposing and has a fair idea of how long it takes to do them. Opinions vary but panels that I'm on, and have submitted grants to, like to see a proposed Timeline. It can be rough but reviewers like to be oriented to your plan. As with the budget you do not have to obsess the timeline. You just want to ensure that there is nothing glaringly disconnected between the work you propose to accomplish and the time you've proposed to accomplish it in.
The nature of your proposal is a little bit tricky. I'd say that there are indeed cases where you might have a fairly exploratory or developmental proposal that doesn't fit an R21. Or perhaps you are in a place where evidence of renewing a grant is really important for tenure. So in some limited cases I might recommend doing a three year R01 with the expectation that if things work out as you expect, you'll renew it. I've seen several of these on study section as (successful) competing continuation applications, btw.
In the above analysis, however, you should focus on the experiments you are proposing and not on your relative experience level. Nor on any general perception that it will be "easier" to get the award if you propose it for four instead of five years.
To summarize, my stance is that the current era of NIH grant review has no trouble at all with a 5 year, full modular plan. It is the default expectation for many of us sitting on review panels. It draws no special attention or comment. Since it is so difficult to get each award in the current environment, you want each one to be as large as possible. (And of course Program is going to lop off a module or two as part of their across-the-board strategy to fund as many awards as possible.) People who are new to the system should be treated no differently and in most cases are not.