The PHS Assignment Request Form is an optional component of an NIH grant application that lets an applicant tell NIH’s Center for Scientific Review (CSR) which Institute or Center (IC) should fund the application, which study section (Scientific Review Group) should evaluate it, who has a conflict of interest that should keep them off the review panel, and what specific scientific expertise the panel needs to assess the science. It is not part of the assembled application PDF that reviewers see — it goes only to NIH referral and review staff. It routinely gets confused with two other, unrelated NIH form components already covered on this site: PHS 398 (the legacy paper application kit whose component parts persist inside today’s electronic package) and the PHS Human Subjects and Clinical Trials Information form (a study-level form describing the research itself). This page explains what the Assignment Request Form actually does and how those three “PHS” names differ.
What the form actually requests
Every NIH grant application is assigned, during a receipt-and-referral process run through CSR’s Division of Receipt and Referral, to (1) one awarding IC that takes funding responsibility and (2) one study section or Special Emphasis Panel that conducts scientific peer review. NIH staff make both assignments using standard referral guidelines — the applicant does not choose either outcome directly. The Assignment Request Form is the applicant’s structured, official channel for influencing that decision, with four fields:
- Awarding Component (IC) Assignment Suggestions — the applicant lists the two- or three-letter IC acronym(s) (e.g., NCI, NIAID) they believe best match the project’s scientific scope, in priority order.
- Study Section Assignment Suggestions — the applicant lists the study-section code(s) (e.g., AIRT, ZRG1) of the specific Scientific Review Group(s) they believe are the best scientific fit, again without hyphens, parentheses, or spaces.
- Individuals Who Should Not Review Your Application — names of reviewers the applicant believes have a genuine conflict of interest (e.g., a direct competitor, a recent collaborator, someone at the applicant’s own institution), with a brief reason for each.
- Expertise Needed to Review Your Application — specific scientific, methodological, or technical expertise the applicant believes the review panel needs to evaluate the proposal fairly, described in general terms rather than as a request for named reviewers.
NIH’s own guidance on the form (published on grants.nih.gov’s PHS Assignment Information page) is explicit that every field is a request, not an instruction: CSR referral officers and Scientific Review Officers consider the suggestions alongside the application’s actual scientific content and current referral guidelines, and are free not to follow them. Requesting a specific IC or study section does not guarantee that assignment, and NIH does not commit to disclosing a reason when a request isn’t honored.
Who uses the information, and who doesn’t see it
The form’s answers go to CSR’s receipt-and-referral staff and to the Scientific Review Officer once an application is assigned to a study section. They are not included in the assembled application viewed by peer reviewers, and reviewers on the panel are not shown the applicant’s conflict-of-interest suggestions directly — that information instead feeds into NIH’s own, separate conflict-of-interest screening of the review roster, alongside the institutional and personal disclosures reviewers themselves make before every meeting. This is the practical reason the form exists as its own component rather than as a field inside the general application narrative: NIH wants routing and roster information handled by administrative staff, kept out of the scientific record reviewers see, and separated cleanly from the parts of the application evaluated on scientific merit.
Is it required?
No — for most funding opportunity announcements the Assignment Request Form is optional, and many applicants submit an application without it. It becomes required only when a specific FOA’s instructions say so. Because it carries no scientific content, leaving it out does not weaken an application; applicants typically use it when they have a concrete, defensible reason to flag a routing preference or a reviewer conflict, not as a routine formality. Overusing the study-section-suggestion field with a long list of options, or requesting reviewer exclusions without a real conflict, tends to carry less weight with referral staff than a short, well-justified request.
How it differs from PHS 398
PHS 398 was NIH’s original paper-based application kit; its name now refers to the family of component forms (Research Plan, Cover Page Supplement, Biosketch, fellowship and training budget forms) nested inside the modern electronic SF-424 (R&R) submission package. The Assignment Request Form is a separate, distinct component of that same electronic package — it has never been part of the PHS 398 form family, and it addresses routing and reviewer logistics, not scientific content or budget.
How it differs from the PHS Human Subjects and Clinical Trials Information form
The PHS Human Subjects and Clinical Trials Information form (“HSCTI”) describes the research itself, at the level of an individual study: participant population, protections, data and safety monitoring, and (for applications meeting NIH’s clinical-trial definition) additional trial-specific detail. It is required whenever the proposed project involves human subjects research, and its content is central to how reviewers score the application. The Assignment Request Form does the opposite job — it says nothing about the science and is invisible to reviewers, existing purely to help NIH route the application to the right IC and panel before review begins. A single application can include both forms, one, or neither, depending on whether it involves human subjects research (governs HSCTI) and whether the applicant chooses to submit routing suggestions (governs the Assignment Request Form).
Where it fits in the application timeline
The Assignment Request Form is completed and submitted alongside the rest of the application package, before the applicant’s institutional Authorized Organizational Representative submits through Grants.gov or NIH ASSIST. Its effects, however, play out after submission, during the receipt-and-referral stage that happens before a study section roster and meeting date are finalized — see the NIH grant cycle for where referral and assignment sit relative to the rest of the annual review timeline. Once an application has been assigned to a study section and a eRA Commons notification goes out, changing the assignment generally requires a formal, justified reassignment request to CSR rather than a resubmission of this form.
Frequently asked questions
Can I request a specific reviewer be added to my study section?
No. The form’s “expertise needed” field lets an applicant describe the type of scientific or methodological expertise the panel should have, but NIH does not accept requests for named reviewers to be added — only requests to exclude a specific person for a stated conflict of interest.
What happens if I don’t submit the form at all?
Nothing negative. NIH’s Division of Receipt and Referral assigns every application to an IC and study section using its standard referral guidelines whether or not an Assignment Request Form is submitted; the form only adds the applicant’s input to that existing process.
Does requesting a specific study section guarantee my application will be reviewed there?
No. NIH considers the request but makes the final assignment based on the application’s actual scientific content and current referral guidelines, and may assign the application to a different study section than the one requested.
Is the Assignment Request Form the same as an NIH cover letter?
They overlap in purpose but are not the same document. Some NIH funding mechanisms and older guidance referenced a cover letter for similar routing requests; current NIH application packages route that information through the structured Assignment Request Form fields instead, which NIH’s referral staff can parse consistently across thousands of applications each cycle.
