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.