In September, the Atmospheric Modeling and Analysis Division of the USEPA will release version 5.0 of the Community Multiscale Air Quality model. Numerous enhancements to the modeling system have taken place since the last major release of the model in 2009 (v4.7). These changes include updated aerosol module code and structure, updated carbon bond 05 toluene chemistry, primary organic aerosol (POA) aging, terpene secondary organic aerosol (SOA) updates, wind-blown dust module, updated in-line photolysis, implementation of ISORROPIA2, updates to aqueous chemistry, and inclusion of lightning generated NO emissions. In addition to changes to the chemical transport model (CTM), significant changes to the model inputs have also been made, including emissions (e.g. lightning NO emissions) and meteorology (e.g. changes to the WRF assimilation techniques and vertical layer structure). All of these changes together have a significant impact on the model performance as compared to the previous version. The impact of these changes on the CMAQ model estimates is assessed by comparing the model estimates for a 2006 annual CMAQ model simulation with available measurement data across North America for the same time period. This presentation will show results of the evaluation of the CMAQ v5.0 modeling system for the 2006 period, with a specific emphasis on how changes to the WRF meteorology impact the CMAQ model estimates. In addition to presenting the model performance for North America, a similar assessment of model performance for Europe may also be included.