The United States Environmental Protection Agency (EPA) has required an unprecedented insect resistance management (IRM) program as part of the Bollgard™ cotton (Cry1Ac plant-incorporated protectant (PIP) expressed in cotton) registration since it was first registered in 1995. New IRM requirements were mandated as terms and conditions of the September 29, 2001 registration decision following an extensive reevaluation of the risks and benefits of Bollgard™ cotton. IRM models are an important tool in comparing resistance management options and helping the Agency set IRM requirements. Resistance monitoring is needed to determine whether insect susceptibility has changed and whether the IRM plan should be altered. The current registration for Bollgard™ cotton expires September 30, 2006 except for the external, unsprayed structured refuge option which will expire September 30, 2004.