Petty Officer 1st Class Anthony Biello, independent duty corpsman, Group Aid Station, II Marine Expeditionary Force Headquarters Group, II MEF, counsels Master Sgt. William Rivera, field mess manager with MHG, on his ankle injury. Biello attended Independent Duty Corpsman School, which is 12 months long and goes beyond the basics of medicine into anatomy, physiology and how medicines affect the body. - Petty Officer 1st Class Anthony Biello, independent duty corpsman, Group Aid Station, II Marine Expeditionary Force Headquarters Group, II MEF, counsels Master Sgt. William Rivera, field mess manager with MHG, on his ankle injury. Biello attended Independent Duty Corpsman School, which is 12 months long and goes beyond the basics of medicine into anatomy, physiology and how medicines affect the body.