Obesity: ICD-10-CM Code Assignment

Obesity: ICD-10-CM Code Assignment

by John Verhovshek, MA, CPC
Obesity means having too much body fat. Obesity increases the risk of diabetes, heart disease, stroke, arthritis, and some cancers. If you are obese, losing even 5-10 percent of your weight can delay or prevent some of these diseases.
Obesity is a substantial public health crisis in the United States, and internationally, with the prevalence increasing rapidly in numerous industrialized nations. In 2009-2010, the prevalence of obesity among American men and women was nearly 36 percent. Approximately 17 percent (or 12.5 million) of children and adolescents aged 2-19 years are obese.
For correct coding of overweight and obesity, documentation should include:
Severity — Overweight, Obese, or Morbid obesity
Contributing factors — Excessive calories or Drug induced
Association — Pregnancy
Symptoms/Findings/Manifestations — BMI or Alveolar hypoventilation
ICD-10-CM code choices include:
E66.01 Morbid (severe) obesity due to excess calories
E66.09 Other obesity due to excess calories
E66.1 Drug-induced obesity (note: This code contains an instructional note to use an additional code for the adverse effect, if applicable to identify the drug (T36-T50) with fifth or sixth character 5).
E66.2 Morbid (severe) obesity with alveolar hypoventilation
E66.3 Overweight
E66.8 Other obesity
E66.9 Obesity, unspecified
Category E66 contains two instructional notes:

  1. Code first obesity complicating pregnancy, childbirth, and puerperium, if applicable (O99.21) 2. Use an additional code to identify body mass index (BMI) if known (Z68).

Body mass index (BMI) is a measure of body fat based on height and weight that applies to adult men and women. Obesity is diagnosed when an individual’s body mass index (BMI) is 30 or higher. Body mass index is calculated by dividing weight in kilograms (kg) by height in meters (m) squared.

Category BMI
Underweight Below 18.5
Normal 18.5-24.9
Overweight 25.0-29.9
Obesity 30.0 and above

Example 1: The patient is a 44-year-old woman who has gained over 50 pounds in the last 10 years. She is seen today because she would like medical treatment to help her lose weight. The physician examines the patient and suggests that she try to lose weight through diet and exercise, before he prescribes her medication. The physician diagnosed the patient with obesity.
Based on this documentation the patient is diagnosed with obesity; however, there is no documentation of the cause, or of her BMI. Because of the lack of detail, the correct code is E66.9 Obesity, unspecified.
Example 2: A 53-year-old female is seen for obesity. She has a 10 year history of type 2 diabetes mellitus. She complains of fatigue, difficulty losing weight, and no motivation. She denies polyuria, polydipsia, polyphagia, blurred vision, or vaginal infections. She states she has gained an enormous amount of weight since being placed on insulin 6 years ago. She eats in excess of 2000 calories a day. She eats only 3 meals a day but eats a lot of snacks through the day. On exam, her height is 5’1” and her weight is 265lb, BMI is 50.1. Her blood pressure is 120/80 mmHg. The remainder of her physical exam is unremarkable.
Assessment: Morbid obesity, Type 2 diabetes mellitus
Based on this documentation, the patient is diagnosed with morbid obesity due to excess calories, which would be coded E66.01 Morbid (severe) obesity due to excess calories. The patient has a body mass index of 50.1, which would be coded Z68.43 Body mass index (BMI) 50-59.9, adult. The patient also has Type 2 diabetes without complication (E11.9 Type 2 diabetes mellitus without complications), with long term, current use of insulin (Z79.4 Long term (current) use of insulin).

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John Verhovshek
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About Has 576 Posts

John Verhovshek, MA, CPC, is a contributing editor at AAPC. He has been covering medical coding and billing, healthcare policy, and the business of medicine since 1999. He is an alumnus of York College of Pennsylvania and Clemson University.

13 Responses to “Obesity: ICD-10-CM Code Assignment”

  1. Debi Bales LVN CPC CRC says:

    So what if the patient has a BMI of 36 and physician documents morbid obesity and the patient also has DM, HTN would the provider have to link in his/her documentation a cause and effect in order to code Morbid obesity E66.01?

  2. Diane Escandell says:

    Can anyone confirm how you would code for a child or pediatric patient documented as obese or greater than the in the 99th percentile by the provider. E66.01 or E66.9?

  3. Marija says:

    Dear John,
    So what if the patient has a BMI of 36 and physician documents morbid obesity and the patient also has DM, HTN would the provider have to link in his/her documentation a cause and effect in order to code Morbid obesity E66.01?
    Do we have some reference material we can use?
    Thank you,

  4. CJones, CPC says:

    See article on BMI Coding ICD-10-CM http://www.cco.us/icd-10-for-bmi-body-mass-index-coding/. Note:
    Overweight and obesity E66- >
    Use Additional code to identify body mass index (BMI), if known (Z68.-).
    BMI adult codes are for use for persons 21 years of age or older
    BMI pediatric codes are for use for persons 2-20 years of age. These percentiles are based on the growth charts published by the Centers for Disease Control and Prevention (CDC). http://www.cdc.gov/growthcharts/clinical_charts.htm

  5. CJones, CPC says:

    BMI adult codes (Z68.1- thru Z68.4-) are for use for persons 21 years of age or older.
    BMI pediatric codes (Z68.5-) are for use for children 2-20 years of age. These percentiles are based on the growth charts published by the Centers for Disease Control and Prevention (CDC). http://www.cdc.gov/growthcharts/clinical_charts.htm 
    After reviewing these CDC pediatric growth charts, we have found that any child (age 2-20) with a documented BMI of 32 or above, will fall into the BMI pediatric of 95th percentile or above, code Z68.54 assignment as a secondary code. 
    Assign codes E66.9, and Z68.54 for child with documentation of obesity with BMI of 32.0-39.9, or BMI pediatric 95-99th percentile or above. 
    Assign codes E66.01, and Z68.54 for child with documentation of morbid obesity with BMI of 40 or above, or BMI pediatric 99th percentile or above. 
    See also 2017 ICD-10-CM Official Coding & Reporting Guidelines
    Guideline I.B.14 Documentation for BMI, Depth of Non-pressure ulcers, Pressure Ulcer Stages, Coma Scale, and NIH Stroke Scale
    Documentation for BMI
    For the Body Mass Index (BMI), 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 ). However, the associated diagnosis (such as overweight, obesity) 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.
    The BMI codes should only be reported as secondary diagnoses. 

  6. Jeannie Gabbard says:

    You state ‘The BMI codes should only be reported as secondary diagnoses.’
    I often see ‘Abdomen: Obese’ in the Exam portion of the visit and then in the Assessment the only diagnosis is BMI.
    For example:
    Assessment: Body mass index (BMI) 33.0-33.98, adult (Z68.33) Improved per today’s measurement.
    Patient Plan: continued vigilance towards lifestyle modifications, nutritional balance with goals towards weight reduction.
    Plan orders: Today’s instructions/counseling include(s) Dietary management education, guidance, and counseling.
    Would I then need to add Obesity, unspecified E66.9 since it was documented in the Exam portion?

  7. Melanie O. says:

    I am curious as to, if the morbid obesity with a BMI of 35-40 is validated with just only DM HTN mentioned, or if it requires linkage..>?
    Does anyone have any reference on this?

  8. Marcy Florence says:

    I too am curious if it is appropriate to code a BMI code by it’self without an E66.- code? I understade that BMI codes are secondary codes but nowhere in the guidelines does it say they are secondary to E66.-.

  9. Stephanie P. says:

    Not sure about the others here, but we get denials all the time for coding the E66 as primary diagnosis (primarily from Medicaid). We’ve found that using the BMI as primary tends to work, but it causes some problems for our pediatricians who see over-weight patients under the age of 2.

  10. Cherlyn says:

    I have a question regarding coding for Obesity. Does documentation have to state “obesity” or “Morbid obesity”? or is just “obese” good enough? I have been told that if just “obese” is documented were not allowed to pick up. Just want better clarification on this.

  11. Cynthia Curtin says:

    you state the age range for pediatric but when coding medicare considers 17 the oldest for pediatric. I have come across many where morbid obesity is documented bmi is 40 or over so pediatric is over 95th but can’t use the bmi because the patient is 19 and on medicare? what do you suggest I use for these cases, it will not accept adult bmi either.

  12. valerie fernandez says:

    I would be interested to know whether documentation by the provider of Class III obesity could be translated to E66.01 morbid obesity
    Please advise Thank you

  13. DENA PETERSEN says: