Clavibacter michiganensis subsp. michiganensis is an important Gram-positive phytopathogenic bacteria that causes bacterial wilt and canker in tomato. The genome of the type strain, NCPPB382, has been sequenced and annotated, however comparative genomics suggests that certain regions are under- or misannotated. In order to improve the genome annotation, we have undertaken a proteogenomic study of this important pathogen. Samples were grown in culture and the proteome of the pellet and supernatant were analyzed separately using shotgun HPLC-MS/MS. These proteomics datasets were analyzed and a number of missing gene were found and a number of existing gene calls were modified.