I’ve been asked this a lot lately, so without further ado …
Application type – Activity code – Institute – Serial no. – Suffix (Year – Amendment -Supplement)
1 R01 AI 83723 01 A1 S1
Number on a grant application identifying application type (e.g., new is type 1), activity code (e.g., research project grant is R01 ), organization to which it is assigned (e.g., NIAID is AI), serial number assigned by the Center for Scientific Review, suffix year showing the support year (budget period) for a grant, amendment (if resubmitted), and other information, e.g., administrative supplement, fellowship institutional allowance. For contracts, the suffix is replaced by a modification number.
Application type is the first digit on an application identification number:
Type 1 — New — provides PHS support for a new research project grant.
Type 2 — Renewal — extends a project period that would otherwise expire for one or more grant budget periods; applications are peer reviewed and compete for funding.
Type 3 — Supplement, a.k.a. administrative supplement — adds funds to a grant without peer review.
Type 4 — Extension — provides time and funds beyond recommended levels. Applies only to MERIT and Small Business Innovation Research Fast Track applications.
Type 5 — Noncompeting continuation — continues support in the out years of a grant; does not compete for funds.
Type 6 — Change of grantee — transfers a grant when one organization buys out another, also called successor of interest.
Type 7 — Change of grantee — transfers a grant from one institution to another.
Type 8 — Change of NIH institute — transfers a grant from one institute to another.
Type 9 — Change of institute — continues support for grant transferred from one institute to another.
Activity code is the 3-digit identifier of an award type, e.g., R01 is a research project grant. Activity codes are grouped together to form funding mechanisms. The major mechanism series are:
F — fellowships
K — career development awards
N — research contracts
P — program project and research center grants
R — research project grants
S — research-related programs (equipment etc.)
T — training grants
U — cooperative agreements
Y — interagency agreements
The two-letter code indicates the primary funding institute (more & more awards will be shared, but only the primary IC is incorporated in the grant application number). Most are relately obvious (HL=NHLBI, DK=NIDDK), but others are less so (HS=AHRQ, TW=FIC), but you can check the NIH abbreviation glossary for clarification.
The serial number is assigned by the Center for Scientific Review (CSR).
The suffix starts with and often only includes the current funding year (-01 for first year etc.). In years in which an amended application (resubmission) is funded, an A1 will be appended to the year if the application was funded on its first amendment or A2 if the application was funded on its second & final amendment/resubmission. Applications for diversity or administrative supplements are identified by incorporation of an “S”, with the number referring to whether this is the first, second, etc. supplement requested for the parent grant (which has its own separate number *without* the “S” in the suffix.