Members 1st Federal Credit Union has been open since 1950. It's the 3rd largest credit union in Pennsylvania with assets totaling $4.45 Billion and providing banking services to more than 433,000 members. Membership: The credit union is a member-owned financial cooperative providing financial banking services to multiple member groups, but primarily serves the military, i.e. members in the armed forces. Membership is also open to immediate family of current members