Field of membership is limited. It's based on select employee groups including staff members of the World Bank Group and the International Monetary Fund. See site for more details. Branches are located in Washington DC.
The credit union is federally insured by the NCUA (Charter # 5582). Considering the small FOM, it is a sizable credit union with $2.17 billion in assets and 55,448 members.
Thanks to the reader who emailed me info on this certificate promotion.