Navy Federal's field of membership is determined by the National Credit Union Administration.
If you fall under any of these categories, you're 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
All Army and Air National Guard Personnel—civilian employees, retirees and annuitants
All Delayed Entry Program (DEP) Personnel
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
Once your family members have joined, they can extend the membership opportunity to their family members, too.
To join visit https://www.navyfederal.org/about/what-you-need-to-apply.php.