ARMY NAVY MARINE CORPS O1 Second Lieutenant 2LT Ensign ENS Second Lieutenant 2nd Lt.  O2 First Lieutenant 1LT Lieutenant Junior Grade LTJG First Lieutenant 1st Lt. O3 Captain CPT Lieutenant LT Captain Capt. O4 Major MAJ Lieutenant Commander LCDR Major Maj. O5 Lieutenant Colonel LTC Commander CDR Lieutenant Colonel Lt. Col. O6 Colonel COL Captain…