Coding BMI

We often receive questions about when certain conditions can be coded.  Most often, the questions are about whether or not anything (everything) a physician or physician extender writes down can be coded. Almost always, the answer is that the condition must be:

• Documented
• Supported by the history, physical examination or clinical condition of the patient

When it comes to secondary diagnoses, they must meet the definition of a reportable additional diagnosis per coding guidelines.  From the Coding Guidelines: "As with all other secondary diagnosis codes, the BMI and pressure ulcer stage codes should only be assigned when they meet the definition of a reportable additional diagnosis (see Section III, Reporting Additional Diagnoses)."

According to Coding Clinic, 2Q 2010 the associated diagnosis (such as overweight, obesity, or underweight) must be documented by the provider.  If no associated diagnosis is documented, then the recorded BMI cannot be coded.