Activity Codes

NIH uses three-character activity codes to differentiate the wide variety of research-related programs NIH supports. The first character typically identifies the major funding category or program type. For example, activity codes for research and development often start with "R," training with "T," fellowship with "F," and career development with "K." Each institute and center (IC) participates in a subset of activity codes. Although each activity code has a broadly defined purpose, there may be differences in their use from one IC to another. Applicants should always refer to the funding opportunity for the specific requirements and details of an initiative.

Activity Code ▼ Funding Category Title Description
R33 Research and Development Exploratory/Developmental Grants Phase II The R33 award is to provide a second phase for the support for innovative exploratory and development research activities initiated under the R21 mechanism. Although only R21 awardees are generally eligible to apply for R33 support, specific program initiatives may establish eligibility criteria under which applications could be accepted from applicants demonstrating progress equivalent to that expected under R33.

This page last updated on: December 10, 2024
For technical issues E-mail OER Webmaster