Last Updated: 01/07/20 ICD-10 Codes International Classification of Disease 10th Edition DIAGNOSIS CODE Learn More CPT Codes Current Procedure Terminology PROCEDURE CODE Learn More Modifiers & Qualifiers Additional Information to Explain the Procedure ADDITIONAL INFO Learn More Medical coding is made up of 3 categories. These universal coding categories are intended to explain both what and why for any medical procedure or encounter.  If done correctly, the codes themselves replace the need for a narrative. I like to look at the Why, before the What. Why do I believe this procedure has Medical Necessity?  If the patient is suffering from certain health conditions i.e., Diabetes, Heart Failure, Pregnancy, Sleep Apnea, Acid Reflux or Infection or certain symptoms i.e., Dry Mouth,