2027 ICD-10-CM Diagnosis Code E66Overweight and obesity

ICD-10-CM Codes›E00–E89›E65-E68›E66

ICD-10-CM E66
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

E66 is a non-billable ICD-10-CM category code for overweight and obesity, so it cannot be submitted on claims. Use a more specific code from this category instead, such as E66.01, E66.09, E66.1, and E66.2.

Code Identity

ICD-10-CM Code
E66
Billable Status
No — Non-Billable Category
Code Describes
Overweight and obesity
Short Description
Overweight and obesity
Same as the full description in the CMS dataset.
Chapter
E65-E68
Overweight, obesity and other hyperalimentation

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE65-E68Overweight, obesity and other hyperalimentation
CategoryE66Overweight and obesity
This CodeE66Overweight and obesity

Specific Coding for Overweight and obesityOverview

Non-specific codes like E66 require more characters. Use one of these billable codes instead:

  • E66.0 for Obesity due to excess calories

  • Use E66.01 for Morbid (severe) obesity due to excess calories

  • Use E66.09 for Other obesity due to excess calories

  • Use E66.1 for Drug-induced obesity

  • Use E66.2 for Morbid (severe) obesity with alveolar hypoventilation

  • Use E66.3 for Overweight

  • E66.8 for Other obesity

  • E66.81 for Obesity class

  • Use E66.89 for Other obesity not elsewhere classified

  • Use E66.9 for Obesity, unspecified

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to E66: its own notes plus those printed at Chapter 4. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From Chapter 4 (E00-E89) Endocrine, nutritional and metabolic diseases applies to 973 codes
  • transitory endocrine and metabolic disorders specific to newborn (P70-P74)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

  • adiposogenital dystrophy (E23.6)
  • lipomatosis dolorosa [Dercum] (E88.2)
  • lipomatosis NOS (E88.2)
  • Prader-Willi syndrome (Q87.11)

Code First

The underlying condition named in the note is sequenced before this code.

  • obesity complicating pregnancy, childbirth and the puerperium, if applicable (O99.21-)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

  • code to identify body mass index (BMI), if known, for adults (Z68.1-Z68.45) or pediatrics (Z68.5-)

Notes

General instructions on how these codes are used.

From Chapter 4 (E00-E89) Endocrine, nutritional and metabolic diseases applies to 973 codes
  • All neoplasms, whether functionally active or not, are classified in Chapter 2. Appropriate codes in this chapter (i.e. E05.8, E07.0, E16-E31, E34.-) may be used as additional codes to indicate either functional activity by neoplasms and ectopic endocrine tissue or hyperfunction and hypofunction of endocrine glands associated with neoplasms and other conditions classified elsewhere.

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name E66, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming E66: they are not reported together with it, unless the two conditions are unrelated.

Code First 1

These codes say to code first a condition named in the note, and E66 is one of the conditions named.

Use Additional Code 2

These codes say to use an additional code from the note, and E66 is one of the codes named.

  • E88.81 Metabolic syndrome and other insulin resistance
    obesity (E66.-)
  • O99.21 Obesity complicating pregnancy, childbirth, and the puerperium
    code to identify the type of obesity (E66.-)

Patient EducationClinical

Body Weight

Body weight is the total mass of your body. Keeping track of your weight is one way to check for changes in your health, but it can't tell you the whole story. That's because your weight includes muscle, bone, fat, and water. Also, everyday factors can play a role in your weight, such as your:

The full article covers:

  • What is body weight?
  • What factors help determine a healthy body weight?
  • What are body weight ranges?
  • What if I have a sudden gain or loss of weight?
  • How can I maintain a healthy body weight?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About E66Overview

What is the ICD-10 code for overweight and obesity?

E66 is the ICD-10-CM category for overweight and obesity, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is E66 (Overweight and obesity) a billable code?

No. This is a category header that groups the codes for overweight and obesity, and headers cannot be submitted on claims. Claims for overweight and obesity need a more specific code from this category, such as E66.01, E66.09, and E66.1.

Does E66 need an additional code?

When the condition applies, yes. The Use Additional Code note reads: code to identify body mass index (BMI), if known, for adults (Z68.1-Z68.45) or pediatrics (Z68.5-). The additional code is reported after E66.