The Office of Insular Affairs (OIA) provides discretionary funding to the U.S. territories of American Samoa, Guam, the Commonwealth of the Northern Mariana Islands, and the U.S. Virgin Islands, as well as the three freely associated states which are the Federated States of Micronesia, the Republic of the Marshall Islands, and the Republic of Palau.
The OIA discretionary funding programs are the Technical Assistance Program (TAP), the Maintenance Assistance Program (MAP), and the Coral Reef and Natural Resources Initiative (CRNR) that includes funds to combat invasive species, the Brown Tree Snake Program, and the Energizing Island Communities (EIC) program.
All OIA discretionary funds when made available, usually in the Fall at the beginning of the new fiscal year, are posted on Grants.gov under CFDA# 15.875.
There are other OIA funding programs that are specific and targeted for certain purposes. Simple descriptions are provided in the link above and additional information may be found in the OIA Budget or the Press Release Archive.