Our physicians do their own coding in our facility and they don't like to use secondary codes. Both the codes for Morbid Obesity and BMI codes above 40 map to an HCC. If the physician properly documents and codes morbid obesity, do they have to also code BMI? If they do not have to code for BMI, can anyone tell me why BMI greater than 40 would map to an HCC? My thoughts are that since it is a secondary code it would never be used alone, and if it's not required to be with morbid obesity, why does it map?