NFCU is by far the largest military CU, I think, at this point, and serves all the Armed Services with the exception of Coast Guard, with a further exception that USCGA cadets
are eligible. See clip from
www.navyfederal.org
Eligibility Checklist
Navy Federal's field of membership is determined by the National Credit Union Administration. If you are in any of these categories, you are eligible to join:
All Department of Defense (DoD) uniformed personnel—Army, Marine Corps, Navy and Air Force, retirees and annuitants
All Department of Defense Reservists—Army, Marine Corps, Navy and Air Force retirees and annuitants
All Army and Air National Guard Personnel—civilian employees, retirees and annuitants
All DoD Officer Candidate programs: Midshipmen and cadets at the United States Naval Academy, United States Military Academy, United States Air Force Academy, United States Coast Guard Academy and the United States Merchant Marine Academy; Other Officer Programs
U.S. Government employees assigned to DoD installations (including Coast Guard)
All DoD civilian employees - including retirees and annuitants
DoD contractors assigned to U.S. Government installations
Family Members, including grandparents, parents, spouses, siblings, grandchildren, children (including adopted and stepchildren) and household members
USAA
USAA = United Services Automobile Association, see
https://www.usaa.com/inet/ent_utils...saa_who_we_are&wa_ref=wcu_main_tab_who_we_are
A large majority of Navy, Marine and CG officers and enlisted personnel have both USAA and NFCU, and no one else, for their financial needs, because of the understanding of the military lifestyle.