ICD-10-CM Code E66.9

Obesity, unspecified

Version 2020 Billable Code Questionable Admission Codes

Valid for Submission

E66.9 is a billable code used to specify a medical diagnosis of obesity, unspecified. The code is valid for the year 2020 for the submission of HIPAA-covered transactions. The ICD-10-CM code E66.9 might also be used to specify conditions or terms like attends obesity monitoring, attends slimming clinic, body mass index 30+ - obesity, central obesity, childhood obesity, choroideremia, etc

The code E66.9 is not usually sufficient justification for admission to an acute care hospital when used as a principal diagnosis.

Short Description:Obesity, unspecified
Long Description:Obesity, unspecified

Tabular List of Diseases and Injuries

The Tabular List of Diseases and Injuries is a list of ICD-10 codes, organized "head to toe" into chapters and sections with guidance for inclusions, exclusions, descriptions and more. The following references are applicable to the code E66.9:

Inclusion Terms

Inclusion Terms
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
  • Obesity NOS

Index to Diseases and Injuries

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code E66.9 are found in the index:

Code Edits

The Medicare Code Editor (MCE) detects and reports errors in the coding of claims data. The following ICD-10 Code Edits are applicable to this code:

  • Questionable admission codes - Some diagnoses are not usually sufficient justification for admission to an acute care hospital. For example, if a patient is given code R030 for elevated blood pressure reading, without diagnosis of hypertension, then the patient would have a questionable admission, since elevated blood pressure reading is not normally sufficient justification for admission to a hospital.


The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Attends obesity monitoring
  • Attends slimming clinic
  • Body mass index 30+ - obesity
  • Central obesity
  • Childhood obesity
  • Choroideremia
  • Choroideremia with deafness and obesity syndrome
  • Cognitive impairment, coarse facies, heart defects, obesity, pulmonary involvement, short stature, skeletal dysplasia syndrome
  • Colobomatous microphthalmia
  • Colobomatous microphthalmia, obesity, hypogenitalism, intellectual disability syndrome
  • Deafness, encephaloneuropathy, obesity, valvulopathy syndrome
  • Difficulty maintaining weight loss
  • Excess subcutaneous fat
  • Finding of body mass index
  • Generalized obesity
  • Has seen dietitian - obesity
  • Impaired glucose tolerance in obese
  • Increase in body fat
  • Increased body mass index
  • Intellectual disability, obesity, brain malformation, facial dysmorphism syndrome
  • Intellectual disability, obesity, prognathism, eye and skin anomalies syndrome
  • Intellectual disability, seizures, macrocephaly, obesity syndrome
  • Lifelong obesity
  • Lower body obesity
  • Lymphedema associated with obesity
  • Mixed conductive AND sensorineural hearing loss
  • MOMO syndrome
  • O/E - obese
  • O/E - overweight
  • O/E - weight
  • Obese
  • Obese build
  • Obese class I
  • Obese class II
  • Obesity
  • Obesity associated disorder
  • Obesity by adipocyte growth pattern
  • Obesity by age of onset
  • Obesity by age of onset
  • Obesity by contributing factors
  • Obesity by fat distribution pattern
  • Obesity in mother complicating childbirth
  • Obesity monitoring check done
  • Obesity monitoring default
  • Obesity monitoring deleted
  • Reason for obesity therapy - occupational
  • Seen by dietitian
  • Sees or has seen dietician
  • Simple obesity
  • Treatment of obesity changed
  • Treatment of obesity started
  • Type 2 diabetes mellitus in obese
  • Understands reducing diet
  • X-linked intellectual disability, hypogonadism, ichthyosis, obesity, short stature syndrome

Clinical Information

  • OBESITY METABOLICALLY BENIGN-. a sub phenotype of obese individuals who have a risk for cardiovascular diseases between that of healthy individuals with normal weight and unhealthy individuals with obesity.
  • OBESITY MANAGEMENT-. an integrated professional approach to screening evaluation control and reduction of abnormal weight gain.
  • OBESITY-. a status with body weight that is grossly above the acceptable or desirable weight usually due to accumulation of excess fats in the body. the standards may vary with age sex genetic or cultural background. in the body mass index a bmi greater than 30.0 kg/m2 is considered obese and a bmi greater than 40.0 kg/m2 is considered morbidly obese morbid obesity.
  • OBESITY MORBID-. the condition of weighing two three or more times the ideal weight so called because it is associated with many serious and life threatening disorders. in the body mass index morbid obesity is defined as having a bmi greater than 40.0 kg/m2.
  • OBESITY HYPOVENTILATION SYNDROME-. hypoventilation syndrome in very obese persons with excessive adipose tissue around the abdomen and diaphragm. it is characterized by diminished to absent ventilatory chemoresponsiveness; chronic hypoxia; hypercapnia; polycythemia; and long periods of sleep during day and night hypersomnolence. it is a condition often related to obstructive sleep apnea but can occur separately.
  • OBESITY ABDOMINAL-. a condition of having excess fat in the abdomen. abdominal obesity is typically defined as waist circumferences of 40 inches or more in men and 35 inches or more in women. abdominal obesity raises the risk of developing disorders such as diabetes hypertension and metabolic syndrome.
  • PEDIATRIC OBESITY-. body mass index in children ages 2 12 and in adolescents ages 13 18 that is grossly above the recommended cut off for a specific age and sex. for infants less than 2 years of age obesity is determined based on standard weight for length percentile measures.

Diagnostic Related Groups

The ICD-10 code E66.9 is grouped in the following groups for version MS-DRG V37.0 What are Diagnostic Related Groups?
The Diagnostic Related Groups (DRGs) are a patient classification scheme which provides a means of relating the type of patients a hospital treats. The DRGs divides all possible principal diagnoses into mutually exclusive principal diagnosis areas referred to as Major Diagnostic Categories (MDC).
applicable from 10/01/2020 through 09/30/2020.


Convert E66.9 to ICD-9

  • 278.00 - Obesity NOS (Approximate Flag)

Code Classification

  • Endocrine, nutritional and metabolic diseases (E00–E90)
    • Overweight, obesity and other hyperalimentation (E65-E68)
      • Overweight and obesity (E66)

Code History

  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016
    (First year ICD-10-CM implemented into the HIPAA code set)
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020

Information for Patients


Obesity means having too much body fat. It is different from being overweight, which means weighing too much. The weight may come from muscle, bone, fat, and/or body water. Both terms mean that a person's weight is greater than what's considered healthy for his or her height.

Obesity happens over time when you eat more calories than you use. The balance between calories-in and calories-out differs for each person. Factors that might affect your weight include your genetic makeup, overeating, eating high-fat foods, and not being physically active.

Obesity increases your risk of diabetes, heart disease, stroke, arthritis, and some cancers. If you have obesity, losing even 5 to 10 percent of your weight can delay or prevent some of these diseases. For example, that means losing 10 to 20 pounds if you weigh 200 pounds.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases

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