FL 44 ??? ??? ??? The _______ ______is reported in FL 42 on the CMS-1450 (UB-04) to describe the category of services as defined by the National Uniform Billing Committee (NUBC). four-digit, service ??? ??? ??? The admitting diagnosis code describes the condition, sign, symptom, illness, injury, disease, or other reason why the patient was admitted and it is entered in this field.