A supplement is a process by which funds are added to an existing grant or cooperative agreement. NIMH supports several types of supplements (Revisions, Administrative, and Research), and the distinctions between these supplements are described below. More detailed NIMH-specific information on each of the types of supplements, as well as the eligibility criteria and application procedures for each, can be found by clicking on the links below. Principal Investigators (PIs) are encouraged to read the information provided on these linked web pages. In addition, PIs are strongly encouraged to contact the Program Officer assigned to their grant with questions related to developing a supplement application.