Coding corner update: Documentation is key when coding morbid obesity

Beginning Oct. 1, 2015, the transition to ICD-10-CM will affect every area of health care. Many codes contain much greater specificity. In the next several issues of The Record, you’ll find a series of revised “Coding corner” articles that include updated codes to align with the transition to ICD-10-CM.

With an increasing number of Americans becoming overweight or suffering from obesity, it’s important for physicians to recognize the degree of obesity and how its complications negatively impact a patient’s health.

ICD-10-CM codes for overweight, obesity, morbid obesity and severe obesity, whether they’re due to excess calories, drugs or with alveolar hypoventilation, are distinct diagnoses that should be properly documented.

The Centers for Medicare & Medicaid Services includes morbid (severe) obesity (ICD-10-CM code E66.01) and associated body mass index values (40 and above - ICD-10-CM code range Z68.41 to Z68.45) in its 2015 Hierarchical Condition Categories Model. This categorization impacts the way providers should document the condition. In ICD-10-CM, a provider must document the cause of obesity, whether it occurs from excess calories or it’s drug-induced. Morbid (severe) obesity with alveolar hypoventilation also has its own code, E66.2.

From a coding perspective, documentation of morbid (severe) obesity due to excess calories in the medical record makes it easier to assign code E66.01, with an associated Z code. Problems can appear when “obesity” is documented in the medical record, but evidence shows that the patient is morbidly obese. For example, the patient has a body mass index of 40 with co-morbid conditions.

Can a BMI value of 40, with co-morbid conditions, be used to validate the HCC model for morbid (severe) obesity when there is a different diagnosis? “Yes,” if you use the following guidelines for making a morbid obesity diagnosis:

• Patients, with a BMI greater than 35, who are seen with co-morbid conditions such as osteoarthritis, sleep apnea, diabetes, coronary artery disease, hypertension, hyperlipidemia and gastroesophageal reflux disease
• Patients with a BMI equal to or above 40 (for adults, Z68.41 to Z68.45)

According to Dr. Laurrie Knight, associate medical director for BCBSM, “You should capture all of the medical complications associated with an obesity diagnosis. For example, sleep apnea, uncontrolled diabetes, hypertension and hyperlipidemia, among others. This will prompt you to define and document the specific clinical condition, for example, morbid or severe obesity due to excess calories.”

“The BMI value is a key element to consider when assessing morbid obesity,” Knight added. “Clinical complications should also be evaluated and treated. Sometimes many interventions are needed to evaluate and identify a clinical condition like morbid obesity. Seeing the impact of weight on other medical conditions is often a clear indicator.”

A provider may recommend several interventions, including seeing a dietician, incorporating an exercise regiment and education about managing other co-morbidities, which can impact the patient’s overall health.

“Morbid obesity may not be documented early in the year as you may opt to evaluate the patient over time,” said Knight. “However, once you’ve determined the patient is morbidly obese, and you code it that way, the diagnosis must continue to be coded as morbid obesity on future visits.”

Since documentation is key to coding morbid obesity, a coder must review the medical record thoroughly when obesity, with a BMI of 40 or above, is documented with co-morbid conditions affecting the patient’s overall health. In this situation, a code for the BMI (the same HCC as morbid obesity) should be used to support morbid obesity. A provider, such as a dietician, can report the BMI, but only the physician can state the diagnosis of morbid obesity, including the cause.

ICD-10 coding for all conditions should follow coding conventions, chapter specific guidelines and general coding guidelines.

If you have questions or need more information, contact your provider consultant.

None of the information included in this article is intended to be legal advice and, as such, it remains the provider’s responsibility to ensure that all coding and documentation are done in accordance with applicable state and federal laws and regulations.