Principles of cooperative democracy and interaction were adequate to the purposes for which people joined credit unions. Specialization of credit unions to provide financial services to its shareholders requires a particularly strict regulation of membership and acceptable activities. Is necessary that all shareholders of the credit union were members of a single community, would know each other well enough to enjoy mutual trust. Among the U.S. credit unions, there are three groups that differ in terms of assets, shareholders, and business services. The main advantage of credit unions consists in transparency, controllability, governance for shareholders. Credit unions of the open type are still controlled by their members, but at the same time provide services to people who are not its members (external customers). Credit unions are competitors of savings institutions, adding interest on deposits of members. This applies to the shares, as well as to additional funds transferred to the account in the credit union. Taking a decision to join a credit union, citizens create an organization through which they participate in the shared savings by mutual crediting and joint (collective) use of personal savings.