The coding guidelines for BMI have been revised in two areas and extensive coding advice for BMI appeared in the Fourth Quarter 2018 Coding Clinic: The revised guidelines are:
- B.14 Documentation by Clinicians Other than the Patient’s Provider
Code assignment is based on the documentation by patient’s provider (i.e., physician or other qualified healthcare practitioner legally accountable for establishing the patient’s diagnosis). There are a few exceptions, such as codes for the Body Mass Index (BMI), depth of non-pressure chronic ulcers, pressure ulcer stage, coma scale, and NIH stroke scale (NIHSS) codes, code assignment may be based on medical record documentation from clinicians who are not the patient’s provider (i.e., physician or other qualified healthcare practitioner legally accountable for establishing the patient’s diagnosis), since this information is typically documented by other clinicians involved in the care of the patient (e.g., a dietitian often documents the BMI, a nurse often documents the pressure ulcer stages, and an emergency medical technician often documents the coma scale).
However, the associated diagnosis (such as overweight, obesity, acute stroke, or pressure ulcer) must be documented by the patient’s provider. If there is conflicting medical record documentation, either from the same clinician or different clinicians, the patient’s attending provider should be queried for clarification.
- 21.c. Categories of Z Codes
Z68 Body mass index (BMI)
BMI codes should only be assigned when the associated diagnosis (such as overweight or obesity) meets the definition of a reportable diagnosis (see Section III, Reporting Additional Diagnoses). Do not assign BMI codes during pregnancy. See Section I.B.14 for BMI documentation by clinicians other than the patient’s provider.
Based on the above guideline revisions and advice published in the Fourth Quarter 2018 Coding Clinic (p. 77-83) I have summarized the information into a list of dos and don’ts when coding BMI. It will be important to continue monitoring advice for reporting BMI in pregnancy.
| Do assign a code for BMI wen the provider has documented the associated diagnosis such as obesity or malnutrition are documented. BMI codes are noted intended for routine capture. | Do not assign a code for BMI wen the provider has not documented the associated diagnosis such as obesity or malnutrition. |
| Do assign the codes for the associated diagnosis based on documentation by a provider who is a practitioner legally accountable for establishing diagnoses. | Do not assign the codes for the associated diagnosis based on a clinician’s documentation who is not the patient’s provider legally accountable for establishing diagnoses. |
| Do assign codes for obesity and morbid obesity without documentation to support clinical significance when they are documented by a provider as they are always clinically significant. | Do not assign a code for over or under weight when there is no documentation to indicate the clinical significance and they do not meet the definition for reporting other diagnoses. |
| Do assign codes for overweight, obesity or morbid obesity based on the provider’s explicit documentation of these conditions. | Do not assign codes for overweight, obesity or morbid obesity based on clinical criteria or obesity related conditions without substantiating documentation by the provider |
| Do code from documentation from physicians other than the attending physician (i.e., consultants, residents, anesthesiologists, etc.) is acceptable, as long as there is no conflicting information from the attending physician. | Do not code from documentation from physicians other than the attending physician (i.e., consultants, residents, anesthesiologists, etc.) when there is conflicting information from the attending physician. |
| Do code only the appropriate code from subcategory O99.21 Obesity complicating pregnancy, childbirth and the puerperium and an if documented an additional code from category E66 to identify the type of obesity. | Do not assign codes for the body mass index (BMI) during pregnancy. |