Q&A: Coding class three obesity and/or morbid obesity

Q: What if the provider's documentation states both class three obesity and morbid obesity as well as body-mass-index (BMI)? Additionally, if the patient’s BMI is greater than 40, can you automatically assign class 3 obesity E66.813?

A: The American Hospital Association’s Coding Clinic First Quarter 2025 is out, and as suspected, there are a couple of questions related to morbid obesity and class three obesity. I highly encourage everyone to read the Coding Clinic in its entirety. 

Coding Clinic First Quarter 2025 notes on p. 17 that it is not appropriate to assign E66.01, Morbid (severe) obesity due to excess calories, if the provider documents class three obesity, as the obesity has been documented as class three. Furthermore, when the provider documents both class three and morbid obesity, assign only E66.813, Obesity, class three, because the morbid obesity has been further specified (in this case, as class three). This supports the instruction contained in the most recent Official Guidelines for Coding and Reporting.

The provider must still document the diagnosis of obesity to capture the code. The BMI alone will not allow us to capture the obesity code.

I also love reading guidance related to diabetes and the “assumed link.” Coding Clinic First Quarter 2025, p. 35 indicates that it is not appropriate to assume a relationship between venous insufficiency and diabetes mellitus in a patient presenting with a venous stasis ulcer with cellulitis and edema in their lower leg. 

There are also a couple of obstetrics and newborn Coding Clinics in this release that I would encourage you to check out. Happy reading everyone!

Editor’s note: Kelly Sutton, MHL, BSN, RN, CCDS, CCS, CDI education specialist for HCPro answered this question. She can be contacted at Kelly.Sutton@hcpro.com.