Field-of-Membership Expansion

​​​​​​A credit union’s field of membership is the legal definition of who is eligible to join. Credit unions often want to expand their fields of membership to include additional potential members. Federal credit unions operate under one of three kinds of charters: single common bond, multiple common bond, or community. The type of charter under which a credit union operates determines what groups or geographic areas it may serve.

A federally chartered credit union must receive approval from the National Credit Union Administration prior to making changes in its field-of-membership. Chapter II of the NCUA’s Chartering and Field of Membership Manual has complete details about fields of membership and the process for amending them.

What Can We Expand?

  • Occupational common-bond expansion – an employer-based group or persons employed within a Trade, Industry or Profession;
  • Associational common bond expansion – a member-based group meeting the NCUA’s threshold requirement and totality of circumstances test;
  • Underserved area expansion – a geographic area meeting the NCUA’s underserved area requirements (available to only multiple common bonds);
  • Community – a geographic area meeting the NCUA’s definition of a well-defined local community or rural district; and
  • Merged (or purchase and assumption) credit union’s field of membership meeting the NCUA’s requirements.

How Can We Expand?

If you are a multiple common-bond, federally-chartered credit union and you want to add groups of 2,999 members or fewer, the preferred method of request and expansion is our Field of Membership Internet Application (FOMIA). If you get an approval from the FOMIA system you can start serving that group immediately.

NCUA member credit unions wishing to use this system must first acquire a PIN. You can obtain your PIN by contacting the NCUA Office of Credit Union Resources and Expansion at

Most groups can be added quickly through FOMIA. However, if you don’t qualify to use FOMIA (your credit union is not a multiple common bond or if your group is 3,000 or over) you can submit the appropriate form to or call 703.518.1150.

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