Coding BMI

We've gotten several questions lately about the requirements for coding BMI, asking why BMI can't be coded if documented, but there is no documentation by the physician regarding obesity/morbid obesity, etc.

The Official ICD-9 instructions have been revised to indicate that the BMI may be documented by someone who cannot make a diagnosis, such as a dietitian.  However, they go on to state that the BMI is always a secondary diagnosis, and the physician must document the related diagnosis, such as overweight, obesity, etc.

This is further supported by Coding Clinic, Q2, 2010 which confirms that the BMI may be recorded by non-physician clinicians, like nurses or dieticians, but it cannot be reported (coded) unless there is also documentation by the physician of the related condition, such as overweight or obesity.

Therefore, it is not appropriate to assign the code for BMI unless the related diagnosis is also documented and reported.

We hope this helps understand the Official ICD-9 Guidelines for reporting BMI.