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Multiple Principal Investigators

The single PI model does not always work best for multidisciplinary, collaborative research. Another way to enhance expertise is to consider a multiple PI application, which can be very useful for research that needs a team science approach. Team science can bring complementary and integrated expertise to a project and be a powerful strategy for success.

Note that the multiple PI option is usually appropriate only if you are in different fields and could not complete the research without the other person.

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Considerations for a Multiple PI Application

Think carefully before you decide to go this route, especially if you are a new investigator since multiple PI applications have big consequences for you:

  • If your application includes an established PI, it won't qualify for the new investigator payline. You'll qualify for it only if all PIs are new.
  • Once the multiple PI application is funded, you'll lose your new PI status, i.e., you'll no longer be able to apply as a new investigator.
  • You must have time to devote to the project and be at the stage where you can assume duties as a PI. This is not a mentored career development award. The established investigator(s) listed as PIs on your application must also intend to devote the time and effort at the level of the PI.

Here are some reasons that multiple PI applications are often better suited to people who have already had independent grants.

  • It's important that new investigators establish their own "scientific identity," which can be more difficult in a multiple PI situation.
  • It can be more challenging to write a multiple PI application because it is more complex. It can be harder to manage too.
  • You are more locked into the research you proposed when another person is involved than you are when you are on your own. (Read more on that topic in What Is a Grant? linked below.)

For applications designating multiple PIs, you'll need to include a detailed leadership plan that describes the governance and organizational structure of the leadership team and justifies the rationale for using a multiple PI approach. Bringing in another PI who is highly regarded in the field but has an expertise similar to yours, is not a good idea. Learn more in the Tips for Writing a Strong Multiple PI Leadership Plan section below.

If you are proposing multidisciplinary research, either on your own or as part of a multiple PI project, think about the expertise on the review panel. Be clear about why the inclusion of a multidisciplinary approach can accomplish more, and have a higher impact, than if this approach was not used.

Not yet ready for an R01? Explore other ways of participating on a grant besides being a PI that will allow you to demonstrate leadership capabilities, e.g., leading a subproject within a larger project.

Should New PIs Consider a Multiple PI Application?

New PIs, think carefully before you choose to join or create a multiple PI application with an established investigator.

Unless all the PIs on a multiple PI application are new, you will not benefit from your new investigator status, won’t qualify for the new investigator payline, and you will lose your new investigator status for future applications.

Multiple PI applications are often better suited to people who already have grants for the following reasons:

  • It's important that new investigators establish their own identity, which can be more difficult in a multiple PI situation.
  • It can be more difficult to write a multiple PI application because it is more complex. It can be more difficult to manage too.
  • You are more locked into the research you proposed when another person is involved than you are when you are on your own.

Note that the multiple PI option is for collaborative, usually multidisciplinary, research and is usually appropriate only if you are in different fields and could not complete the research without the other person.

If you are conducting multidisciplinary research, make sure NIH has a review committee that will be able to effectively review all aspects of the application.

Completing the Forms for a Multiple PI Application

If you plan to submit a multiple PI application, you must include a Multiple PI Leadership Plan. When you complete the forms, do the following.

  • Do NOT check the co-PIs box on the SF 424 (Cover Page) form. NIH does not use co-PIs.
  • Include the Commons ID for each PI in the "Credential, e.g. agency login" field on the Research and Related Senior/Key Person Profile form.

Put only the contact PI's name and Commons ID on the SF 424 form. He or she must be affiliated with the applicant institution.

Tips for Writing a Strong Multiple PI Leadership Plan

Give time and attention to the required Leadership Plan. Reviewers judge its scientific merit and whether it promotes enough coordination and communication among PIs. They consider the appropriateness and quality of the plan in their evaluation and scoring of the investigators, as well as the overall impact of the application.

To make your plan as sound as possible, the following pointers may help.

Address What's Required 

Before discussing and writing your plan, you and your fellow PIs need to know what items you should cover. They include:

  • Rationale and justification for choosing the multiple PI approach
  • Governance and organizational structure of the team
  • Procedures for resolving conflicts
  • Process for making decisions on scientific direction and allocating funds and resources

Below, we expand on a few of the required items in the section Know What Reviewers Want, Like, and Expect.

Follow a Few Tips 

Here is some general advice to keep in mind as you approach and write your plan. Also check out NIH’s Examples of Project Leadership Plans for Multiple PI Grant Applications.

Consider the appropriateness of the multiple PI approach for new investigators. Don’t miss the key points in the Should New PIs Consider a Multiple PI Application?  section above.

Ask questions. Approach the Leadership Plan as you would the Research Plan. That is, ask yourself and the other PIs some basic questions, such as: Why are we making this a multiple PI application? How will we organize and execute the overall project? What will we do if we run into problems? What provisions can we make ahead of time against potential pitfalls?

Do more than what's required. While good plans address several points required by NIH, e.g., rationale for using the multiple PI approach, governance, conflict resolution, or intellectual property issues, the best plans go a step further. They cover additional ground by discussing potentially sensitive issues, such as data sharing between PIs, collaborative publication policies, contingency plans in case one PI changes institutions, and procedures for allocating resources.

Get organized. Just like exemplary Research Plans, the best Leadership Plans are typically organized into succinct sections or paragraphs with informative headings. For example, you could use the following headings: Rationale, Organizational Structure, and Procedures for Resolving Conflicts.

Dividing the Leadership Plan into sections and clearly labeling them makes for easy reading, which is important for reviewers who have many applications to evaluate. Sections also let reviewers follow your thought processes and find answers to questions they may have.

Since the Leadership Plan has no page limit and does not count toward the Research Strategy page limit, use the lack of space constraints to include what you need and present the information in an easy-to-find way. However, do not try to use this section to circumvent the page limit for the Research Strategy section.

Avoid pitfalls. Weaker Leadership Plans tend to suffer pitfalls: poor organization, lack of specifics on roles and responsibilities, omitting critical information like plans for deciding scientific direction or resolving conflicts, and projecting an attitude of “trust us, we’ve been working together for years.”

Avoid bringing in additional PIs solely because they are prominent in your field. Their prominence does not give you any benefit and can detract from your score if they don’t have a truly distinct and independent role in the project.

Another major pitfall is stating that all PIs will take joint responsibility for everything—finances, project direction, and necessary scientific expertise. Reviewers know that even the closest collaborations can run into problems and that there will be times when PIs do not agree. Therefore, reviewers will appreciate a sensible division of responsibilities much more than a frequently implemented conflict resolution procedure.

Plans with faults like these may sometimes pass scrutiny by reviewers, but you don’t want to take a chance on undermining their confidence in your application by simply recycling a plan from another application.

Know What Reviewers Want, Like, and Expect 

As we mentioned, you should cover several required bases in your Leadership Plan. We focus on a few of those here and provide advice on how you might address them based on what reviewers expect to see.

Why Multiple PIs?

Reviewers like to see a solid, scientifically based answer to this question. Since the multiple PI option is for collaborative, usually multidisciplinary research, they must understand why your proposed research requires bringing in and working with other PIs with distinct and complementary expertise.

In the absence of a clear scientific rationale, reviewers will likely question why you wouldn't be able to complete the research without the other PIs.

What to do. Provide a strong rationale and justification for choosing the multiple PI approach. For instance, describe why the Specific Aims of the project could not be accomplished without the combined leadership and expertise of all the PIs.

Who Will Do What?

Reviewers expect to see Leadership Plans that clearly and specifically delineate the PIs' respective roles and responsibilities. Plans that do may receive more favorable evaluations than plans that don't.

What to do. We touched on this above, but it's worth repeating. Rather than stating that the PIs will share all responsibilities equally, which reviewers usually view as unrealistic, describe specific "assignments": PI #1 will be responsible for Specific Aim #1 and doing X, PI #2 will work on Specific Aim #2 and be in charge of Y, and so on.

Be sure to list who will serve as Contact PD/PI. That person must be affiliated with the institution submitting the application and will coordinate communication among all PIs and NIH as well as completing progress reports.

Organizational Structure

Reviewers look for a sound organizational and governance plan. In the absence of one, they'll be concerned that the level of coordination and communication among the PIs might be insufficient to fully realize the collaborative aspects of the project.

For complex awards, consider a diagram or organization chart to help convey your organizational structure in addition to your governance plan.

When a multiple PI application includes an established researcher and a more junior investigator, reviewers will look for and carefully evaluate the time commitment and plans for decision making and resource allocation to determine whether they are appropriate and equitable. Although the level of effort of each PI on a multiple PI application—whether established or junior—does not have to be the same, it does need to be appropriate and justified for the work proposed.

What to do. In your governance plan, describe the process for deciding scientific direction and communication procedures, such as regularly scheduled meetings of the PIs, periodic evaluation of research progress and finances, and publication policies.

Conflict Resolution 

Reviewers like to see a carefully considered conflict resolution plan, which preferably includes the involvement of well-respected people outside of the project to mediate disputes if the PIs are unable to resolve the issues by themselves.

What to do. Disputes are likely to arise, so you'll need to describe how you'll handle them. If you can't come to an agreement, will you bring in an arbitration committee? If so, who and how many people will be on it? Will you give a timeframe in which the conflict must be resolved?

Find more information on the NIH Multiple Principal Investigators page.


  • My team and I have the required resources to do the work.
  • If not, I plan to request the equipment in the application.
  • My team and I are qualified to execute the experiments.
  • I secured letters of collaboration to put in my application.
  • If I am a new investigator, I am fully aware of the implications of a multi-PI application on my new PI status and other caveats.
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