“Morbid Obesity” has always been supported by BMI values of 40 or more or 35-39.9 with co-morbid conditions and “Overweight” has always been supported by BMI values of 30-34.99 supports.
In ICD 10, when coding from category E66, there is an instructional note to use additional code to identify the BMI, if known.
Is it appropriate to report E66.01 (Morbid Obesity) with a documented BMI of 34.0? Does a BMI of 34.9 and below support the definition of morbid obesity?
I would use E66.09 other obesity due to excess calories, or E66.3 overweight/E66.8 other obesity depending on the BMI instead of morbid obesity codes. I agree 'morbid obesity' should be reserved for BMI 40 and over. You would think there would be a diagnosis for 'obese' instead of 'other obesity', right?
In one facility where I worked previously, a diagnosis of morbid obesity with a BMI that did not clinically support that diagnosis would be considered an inconsistency in documentation that required a query to the provider for clarification.
I don't believe it would be appropriate for a coder to change a provider's diagnosis or choose a code that contradicted what is documented based on a clinical interpretation of that information. After all, you can't tell if it is the provider's diagnosis is that is wrong, or if it was the BMI that was recorded or calculated incorrectly, so no assumptions should be made.