The field of membership for SONEPCO is limited to those having the following common bond:

1. Employees, officials, and persons who work for, and are regularly under contract to, Sierra Pacific Resources, Inc. in Nevada or its subsidiaries.
2. Employees whose companies have a contractual relationship with Nevada Power Co., a subsidiary of Sierra Pacific Resources, Inc.
3. Spouses of person who died while within the field of membership of this credit union; persons retired as pensioners or annuitants from the above employment; employees of this credit union; members of their immediate families or household; and organizations of such persons.
4. Many Select Employer Groups (SEGs) in Nevada.  Full membership eligibility information is available at the main office of SONEPCO.