2026 ICD-10-CM Diagnosis Code E66Overweight and obesity

ICD-10-CM CodesE00–E89E65-E68E66

ICD-10-CM E66
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

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
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

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Code First

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

Use Additional Code

Type 2 Excludes

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

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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About E66Overview

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.