Beginning on January 1, 2001, the National Association of REALTORS® required that all REALTOR® members complete Code of Ethics training at least once every four years. The goal of this requirement is to increase awareness of the Code and decrease instances of unethical behavior. The specifics of the Quadrennial Code of Ethics requirement are as follow:

• Effective January 1, 2001 through December 31, 2004 and for successive four (4) year periods thereafter, REALTORS® are required to complete quadrennial ethics training of not less than two (2) hours and thirty (30) minutes of instructional time. NOTE: The current period is January 1, 2009 through December 31, 2012.
  
• Failure to complete the required periodic ethics training shall be considered a violation of membership duty for which REALTOR® membership shall be suspended until such time as the required training is completed.
• Suspension of membership means suspension of membership rights and privileges and denial of Association services, until the training is completed. Although membership rights, privileges and services are suspended membership, per se, continues and the suspended member remains obligated for payment of membership dues and to abide by the Code of Ethics during the period of suspension

http://www.realtor.org/mempolweb.nsf/pages/quadrennialethicstrainingcourse