Neonicotinoid insecticides, primarily imidacloprid and thiamethoxam, continue to be the backbone of control for populations of Colorado potato beetle (Leptinotarsa decemlineata) in potatoes. While still highly effective in many locations, the repeated use of neonicotinoids can increase the risk of resistance development. Populations from across the United States were evaluated for imidacloprid and thiamethoxam resistance in 2007 using adult topical bioassays. Special emphasis was placed on the recollection of populations in 2007 that had been previously sampled in summer of 2006 to allow comparison of pre- and post-diapause beetles. A portion of the post-diapause beetles were also reared through a complete generation in the laboratory; offspring were bioassayed and values compared with values for the post-diapause beetles. Nationwide, resistance values were consistent with previous years where high levels of resistance were again observed along the East Coast and generally more susceptible populations detected in the Midwest and West. The frequency of measured resistance among populations in the Midwest appears to be increasing, however, with notable increases in estimated LD50 values in both Michigan and Wisconsin where greater than 10 fold resistance to imidacloprid has been documented compared to susceptible beetles. LD50s tended to be lower for post-diapause beetles when compared to summer generation adults from the same population. Monitoring for resistance and cross resistance is a critical tool for resistance management and allows growers and consultants to identify problem populations which can arise rapidly.