Documenting and Coding for Morbid Obesity – HCC 22

Documenting and Coding for Morbid Obesity – HCC 22

  • 15 Nov 2
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Documenting and Coding for Morbid Obesity- HCC 22

By: Dr. Richard Schamp, MD

Frequently we receive questions about documenting and coding for levels of obesity. This is because Morbid Obesity triggers an HCC and thus provides payment, which is appropriate, due to the extra costs involved in the care of the condition.  We would like to provide some clarification around this issue.

Morbid Obesity HCC 22

Several ICD-9 codes currently map to HCC 22 in the CMS-HCC v21 (as well as RxHCC 21).  These include:

  • 278.01   Morbid obesity
  • 278.03   Obesity hypoventilation syndrome
  • V85.4     BMI 40 and over, adult
  • V85.41  BMI 40.0-44.9, adult
  • V85.42  BMI 45.0-49.9, adult
  • V85.43  BMI 50.0-59.9, adult
  • V85.44  BMI 60.0-69.9, adult
  • V85.45  BMI 70 and over, adult

Reporting BMI codes

The ICD-9 Official Coding Guidelines indicate that someone who cannot make a diagnosis, such as a dietitian, may document the BMI.  However, the guidelines state that the BMI is always a secondary diagnosis and the physician must document the related diagnosis, such as overweight, obesity, etc. in a separate note.  If the BMI is noted as a diagnosis in a physician’s note, it may be coded as above and submitted as a diagnosis.

AHA Coding Clinic, Q2, 2010 further supports this, which confirms that the BMI may be recorded by non-physician clinicians, like nurses or dieticians; but it cannot be reported unless also documented by the physician and associated with a related condition, such as overweight or obesity.  Therefore, unless the physician makes a comment on the significance of the BMI, it cannot be coded.

Diagnosing Obesity Hypoventilation Syndrome (OHS)

Obesity Hypoventilation Syndrome (OHS) is possibly more common than Morbid Obesity.  The exact prevalence of OHS in the general population remains unknown and most prevalence data describe subjects with obstructive sleep apnea, wherein its prevalence has been estimated to range from 10% to 38% in different groups. OHS may be an under-diagnosed and under-treated condition in PACE populations.

Diagnostic criteria for Obesity Hypoventilation Syndrome (278.03)BMI >30 kg/m2

  • Awake arterial hypercapnia (PaCO2 >45 mm Hg)
  • Rule out other causes of hypoventilation
  • Polysomnography reveals sleep hypoventilation with nocturnal hypercapnia with or without obstructive apnea/hypopnea events

 Diagnosing Morbid Obesity

The medical literature has multiple definitions and criteria for morbid obesity.

  • The surgical literature promotes a more granular definition and developed the criteria of BMI of 35 or greater with obesity related health conditions or comorbidities.  Most bariatric surgery associations and programs consider this to be morbid obesity.  In fact, CMS itself identifies (Transmittal 2641, Jan 29, 2013) that bariatric surgery for morbid obesity is a covered procedure and only requires a BMI ≥ 35 with comorbidity.
  • The Medical Dictionary for the Health Professions and Nursing defines Morbid Obesity as either: Being sufficiently overweight so as to prevent normal activity or physiologic function or to cause the onset of a pathologic condition or a BMI ≥40.
  • Mosby’s Medical Dictionary, 8th ed says: An excess of body fat, or weight of 100 pounds over ideal body weight, that increases the risk of developing cardiac and endocrine disturbances, including coronary artery disease and diabetes mellitus…
  • Multiple large health insurance companies offer a definition of morbid obesity using some or any of the above criteria.

If a provider diagnoses Morbid Obesity and codes for it, and the documentation includes evidence of the diagnosis affecting patient care, then typical coding guidelines are satisfied.  In the ICD-9 CM coding book, under subcategory 278.0 in the tabular list, there is an instructional note to use an additional code to identify the BMI, if known (V85.0 – V85.54), though this is not required.  Ultimately, providers make diagnoses, not coders.

In spite of the above, the ICD-9-CM still follows the older WHO definition and defines Morbid Obesity as a BMI of 40 or above, which some believe is outdated.  This definition is not carried over to ICD-10, as far as we can see.  Yet, the ICD-9 CM currently offers no instructions to code a patient with BMI between 35 and 40 plus obesity-related comorbidity(ies) as morbid obesity.  Some coders argue that (based on ICD-9 criteria) only patients with BMI ≥40 should be coded as Morbid Obesity.  Thus, this coding situation has become controversial.

Because of this, for those organizations that desire to be conservative in their coding, providers may use the WHO criteria when diagnosing Morbid Obesity.  Organizations that believe a more progressive approach is warranted may choose to use other criteria.

Regardless, we recommend organizations have a policy or protocol in place that spells out your preferred definition of morbid obesity and then follow that in documentation and coding processes. In all cases, be sure that the documentation supports the diagnosis as being current and how it affects care of the participant.


*The information presented here complies with accepted coding practices and guidelines as defined in the ICD-9-CM coding book. It is the responsibility of the healthcare provider to produce accurate and complete documentation and clinical rationale, which describes the encounter with the patient and the medical services rendered, to properly support the use of the most appropriate ICD-9-CM code(s) according to the official coding  guidelines.

*The information presented herein is for general informational purposes for clinicians only and is not warranted that the information contained herein is complete, accurate or free from defects.