Pediatric Coding Alert

Question: Our pediatrician has routinely used E66.9 to code obese patients and E66.01 for patients who are morbidly obese. For a 10-year-old patient whose overeating has led to a body mass index (BMI) of 23, our provider documented E66.9, which I don't believe is the correct code for this encounter. Is there a better code to use?

Utah Subscriber

Answer: According to the Centers for Disease Control (CDC), a BMI of 23 would put a 10-year-old in the 95th percentile for his or her age, giving your patient an official diagnosis of obesity. So, your pediatrician is correct in that E66.01 (Morbid [severe] obesity due to excess calories) would not be a good diagnosis in this case as the patient's condition has not risen to the level of morbidity.

However, E66.9 (Obesity, unspecified) would not be correct either. Most of the E66 (Overweight and obesity ...) codes list different causes - E66.1 (Drug-induced obesity), for example - while others, such as E66.3 (Overweight), point to a BMI that does not fit the diagnosis. So, given the combination of the patient's BMI and its underlying causes, the most accurate diagnosis code to use in this scenario would be E66.09 (Other obesity due to excess calories).

Coding alert: ICD-10-CM guidelines for the E66 codes specify that you should "use [an] additional code to identify body mass index (BMI), if known," pointing to the Z68 (Body mass index [BMI] ...) encounter codes for reporting BMIs.

These codes are age-specific, and the note that accompanies them states that "BMI pediatric codes are for use for persons 2-20 years old." As your patient is 10 and in the 95th percentile for his or her particular age group, the most accurate Z code for your reportingwould be Z68.54 (Body mass index [BMI] pediatric, greater than or equal to 95th percentile for age). And you should also note that some carriers now consider the maximum age for pediatric BMI to be 18; so, if you get a denial for ICD-10 invalid, it could be due to age.