Bethpage Federal Credit Union has been open since 1941. It's the largest credit union in New York and the 16th largest in the United States with assets totaling $8.9 Billion and providing banking services to more than 400,000 members. Membership: The credit union is a community-based financial institution. People living, working, or worshipping in the credit union's geographic area can become a member and access banking services. Membership is also open to immediate family of current members.