NIH guide, generated from the corpus
R21 and R03 parent NOFO requirements
GrantAmp covers investigator initiated applications under the parent R03 and parent R21 NOFOs on Grants.gov. The excerpts below are NIH's own text from the Page Limits table, the Standard Due Dates table, and Section II and Section IV of the parent NOFOs. Read the source before you rely on a summary, and read Section IV of the NOFO you choose, which can set a different limit.
NIH last updated 2026-06-22. GrantAmp's copy retrieved 2026-09-28. Page generated 2026-09-28.
NOFO instructions supersede the Application Guide, and NIH Guide Notices supersede both. NIH's own wording.
In brief
The Page Limits table for R21 and R03
The 6 page Research Strategy rows for R21 and R03 sit in the shared research grants table.
From NIH, How to Apply Application Guide: Page Limits > For R01, R03, R21, RP1, S10, U01, and all other Applications
If no page limit is listed in the table below, in Section IV of the NOFO under Page Limitations, or in a related notice, you can assume the attachment does not have a limit.
Note: Not all application form sets include all the attachments listed below. For example, the S10 does not include the PHS Research Plan form so the Introduction, Specific Aims, and Research Strategy attachment page limits do not apply.
| Section of Application | Activity Codes | Page Limits* (Unless the funding opportunity specifies a different limit) |
|---|
| Project Summary/Abstract | For all Activity Codes | 30 lines of text |
| Project Narrative | For all Activity Codes excluding C06, UC6, and G20. | three sentences |
| Introduction to Resubmission and Revision Applications | For all Activity Codes (including each applicable component of a multi-component application) | 1 page |
| Specific Aims | For all Activity Codes that use an application form with the Specific Aims section (including each component of a multi-component application) | 1 page |
| Research Strategy | For Activity Code DP1 | 5 pages |
| Research Strategy | For Activity Codes R03 , R13 , U13 , U43 , R16 , R21 2 , R35 , R36 , R41 , R43 , SC2 , SC3 , X01 1 , X02 1 , R50 , UT1 1 X01 and X02 opportunities can be either 6 or 12 pages. Review the NOFO for details. 2 R21 page limit may be different when combined with other activity codes. For example, R21/R33. | 6 pages |
| Research Strategy | For Activity Code DP2 | 10 pages |
| Research Strategy | For Activity Codes DP3 , DP5 , G08 , G11 , G13 , RC2 , RC4 , RF1 , R01 , R15 , R18 , R21 / R33 , R24 , R28 , R33 , R34 , R42 , R44 , R61 , R61 / R33 , RL1 , SB1 , SC1 , SI2 , UB1 , UC2 , UH2 , UH3 , UG1 , UC4 , UF1 , UG3 / UH3 , UH2 / UH3 , U01 , U18 , U24 , U2C , U34 , U42 , U44 , UT2 , X01 1 , X02 1 1 X01 and X02 opportunities can be either 6 or 12 pages. Review the NOFO for details. | 12 pages |
| Research Strategy | For all other Activity Codes | Follow NOFO instructions |
| Commercialization Plan | For Activity Codes R42 , R44 , SB1 , UT2 , U44 , UB1 (Attachment 7 on SBIR/STTR Information form) | 12 pages |
| Biographical Sketch (legacy) | For all Activity Codes (including DP1 and DP2 which previously had special page limits) | 5 pages |
| Biographical Sketch Common Form & Biographical Sketch Supplement | For all Activity Codes (including DP1 and DP2 which previously had special page limits) | No hard limit; length controlled through SciENcv data entry format |
Note
Notice of Funding Opportunity (NOFO) instructions always supersede these instructions.
Page Limits NIH date 2026-06-22. Retrieved 2026-09-28.
Standard due dates for new R21 and R03 applications
The row that lists R03, R21, R33, and related codes for new applications.
From NIH, How to Apply Application Guide: Standard Due Dates
The Key Dates section of many funding opportunities indicate standard dates apply. Use the table below and the activity code (e.g., R01) specified in the title of the opportunity to determine application cycles and their relationship to due dates, review and council dates, and earliest possible start dates. Renewal, resubmission, and revision applications may have different due dates than new applications. Read the table carefully.
Standard Due Dates NIH date 2026-03-24. Retrieved 2026-09-28.
PA-25-304 Section II (R21 Clinical Trial Not Allowed)
Award budget, project period, and which applications the parent accepts.
From NIH, Notice of Funding Opportunity: Part 2. Full Text of Announcement > Section II. Award Information
Funding Instrument
Grant: A financial assistance mechanism providing money, property, or both to an eligible entity to carry out an approved project or activity.
Application Types Allowed
New
Resubmission
Revision
The OER Glossary and the How to Apply Application Guide provide details on these application types. Only those application types listed here are allowed for this NOFO.
Clinical Trial?
Not Allowed: Only accepting applications that do not propose clinical trials.
Need help determining whether you are doing a clinical trial?
Funds Available and Anticipated Number of Awards
The number of awards is contingent upon NIH appropriations and the submission of a sufficient number of meritorious applications.
Award Budget
The combined budget for direct costs for the two-year project period may not exceed $275,000. No more than $200,000 may be requested in any single year.
Award Project Period
The total project period may not exceed 2 years.
NIH grants policies as described in the NIH Grants Policy Statement will apply to the applications submitted and awards made from this NOFO.
PA-25-304 NIH Exploratory/Developmental Research Project Grant (Parent R21 Clinical Trial Not Allowed) NIH date 2024-12-18. Retrieved 2026-09-28.
PA-25-302 Section II (parent R03)
The R03 direct cost cap and project period.
From NIH, Notice of Funding Opportunity: Part 2. Full Text of Announcement > Section II. Award Information
Funding Instrument
Grant: A financial assistance mechanism providing money, property, or both to an eligible entity to carry out an approved project or activity.
Application Types Allowed
New
Resubmission
Revision
The OER Glossary and the How to Apply Application Guide provide details on these application types. Only those application types listed here are allowed for this NOFO.
Clinical Trial?
Not Allowed: Only accepting applications that do not propose clinical trials.
Need help determining whether you are doing a clinical trial?
Funds Available and Anticipated Number of Awards
The number of awards is contingent upon NIH appropriations and the submission of a sufficient number of meritorious applications.
.
Award Budget
Application budgets are limited to $50,000 in direct costs per year.
Award Project Period
The total project period may not exceed two years.
NIH grants policies as described in the NIH Grants Policy Statement will apply to the applications submitted and awards made from this NOFO.
PA-25-302 NIH Small Research Grant Program (Parent R03 Clinical Trial Not Allowed) NIH date 2024-12-18. Retrieved 2026-09-28.
Page limitations in the parent NOFOs
Section IV deferral to the Application Guide and the Page Limits table.
From NIH, Notice of Funding Opportunity: Part 2. Full Text of Announcement > Section IV. Application and Submission Information > Page Limitations
All page limitations described in the How to Apply- Application Guide and the Table of Page Limits must be followed.
Instructions for Application Submission
The following section supplements the instructions found in the How to Apply- Application Guide and should be used for preparing an application to this NOFO.
PA-25-304 NIH Exploratory/Developmental Research Project Grant (Parent R21 Clinical Trial Not Allowed) NIH date 2024-12-18. Retrieved 2026-09-28.
From NIH, Notice of Funding Opportunity: Part 2. Full Text of Announcement > Section IV. Application and Submission Information > Page Limitations
All page limitations described in the How to Apply- Application Guide and the Table of Page Limits must be followed.
Instructions for Application Submission
The following section supplements the instructions found in the How to Apply- Application Guide and should be used for preparing an application to this NOFO.
PA-25-302 NIH Small Research Grant Program (Parent R03 Clinical Trial Not Allowed) NIH date 2024-12-18. Retrieved 2026-09-28.
In the app, choose R21 or R03 on the intake and the matching parent NOFO. GrantAmp builds a cited requirements manifest and readiness dashboard from your answers.
Open the appSources
This page is generated from GrantAmp's copy of the NIH pages it cites. The NIH text is shown as NIH published it, with NIH's own date and the date GrantAmp retrieved it. The page is rebuilt whenever GrantAmp's corpus refresh finds that a cited page changed.
NOFO instructions supersede the Application Guide, and NIH Guide Notices supersede both.