Resubmission (A1)

How it works

A resubmission works by revising the original (A0) application based on the summary statement from the study section and resubmitting it under the same project. NIH rules, as of October 2026:

• One resubmission. Each new or renewal application may be resubmitted once. The "A1" suffix marks it.
• 37-month window. The A1 must be submitted within 37 months of the original A0 submission.
• Introduction. A one-page Introduction (unless the funding opportunity says otherwise) summarizes the substantial changes and responds to the main criticisms.
• No change marking. NIH no longer wants changes marked in the text with highlighting, brackets, or other formatting; the Introduction does that job.
• After an unfunded A1. The applicant can submit the same idea as a new (A0) application. NIH does not require it to be substantially changed, but it is reviewed as new, without the earlier summary statements.

Why it matters for researchers

Resubmission matters because a well-revised A1 gets a second, full review with the reviewers' earlier concerns addressed, and many NIH awards come from resubmissions. A good Introduction shows reviewers the applicant took the critique seriously, and addressing the major concerns, not just the easy ones, is what moves the score.

How to write a strong Introduction

The best Introductions open with a sentence thanking reviewers and naming the biggest change, then answer each major criticism in turn. Group related comments, quote or paraphrase each one briefly, and say exactly what changed and where. Reviewers on the second round may be different people, so the Introduction and the revised specific aims page should make sense without the first summary statement.

Common mistakes

• Arguing with reviewers instead of fixing the underlying problem.
• Responding only to the minor points.
• Resubmitting too quickly without new preliminary data when feasibility was the main concern.
• Missing the 37-month window, which forces a new A0 submission.
• Not talking to the program officer about whether an A1 or a different mechanism makes more sense.

Note that resubmissions count toward NIH's limit of six applications per PI per calendar year, in effect since September 2025.

Frequently asked questions