Specialization of credit unions to provide financial services to its shareholders requires a particularly strict regulation of membership and acceptable activities. To reduce the risk of default on loans members of the credit union shall the joint guarantee. National Credit Union Insurance Fund was created by Congress in 1970 to insure deposits of credit union members in the amount of 100 thousand dollars. The value of credit unions is not limited to the role of the economic agent - they are an important element of the social structure and a factor of social stability and progress. Credit cooperatives and credit unions exist in many different forms. The main differences relate to the nature of the membership and the opening of a credit institution. Unlike banks credit unions limit their activities to a closed circle of people.