What does ICD-10 code E66 mean?

ICD-10 code E66 is the standardized code used for overweight and obesity in medical records and coding systems.

When is ICD-10 code E66 used?

Doctors, hospitals, and insurers may use ICD-10 code E66 when recording overweight and obesity in a standardized format. This entry may also act as a broader category that points toward more specific child codes.

Does ICD-10 code E66 confirm a diagnosis?

No. A code helps standardize documentation and claims, but it should not be read as a substitute for a clinician's full assessment.

ICD10

ICD-10 Code E66: Overweight and obesity

Name: ICD-10 Code E66: Overweight and obesity
Creator: HealthAssure Clinical Team
Published: 2026-05-21T06:05:18.954Z

E66 is an ICD-10 diagnosis entry used to group records related to Overweight and obesity. You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen. ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Endocrine, nutritional and metabolic diseases (E00-E89).

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Endocrine, nutritional and metabolic diseases (E00-E89).

When is it used?

May be used when a clinician documents overweight and obesity in a patient's medical record.
May appear in hospital records, claims, referrals, and clinical documentation.
This code may act more like a grouping or parent code, so a more specific child code may be used in final documentation when available.

What it does not mean

A code alone does not explain severity, treatment plan, or outcome.
A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
This entry may represent a broader category rather than the most specific billable code.

Code hierarchy

chapter

4Endocrine, nutritional and metabolic diseases (E00-E89)

block

E65-E68Overweight, obesity and other hyperalimentation

currentE65-E68

Official coding notes

Applicable to

code to identify body mass index (BMI), if known, for adults (Z68.1-Z68.45) or pediatrics (Z68.5-)
obesity complicating pregnancy, childbirth and the puerperium, if applicable (O99.21-)

Excludes2 (may code together if documented)

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

Code first

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

Use additional code

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

Where you may see this code

You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen.

Related specialists

EndocrinologistGeneral Physician

Sibling codes

E65Localized adipositybillable E67Other hyperalimentation E68Sequelae of hyperalimentationbillable

Coding guidelines

Compatibility

Legacy code aligns to an official FY 2026 category. Frontend should resolve to the official category page and surface the billable child codes.

Legacy codes

E66

Replacement codes

E66.1 — Drug-induced obesityE66.2 — Morbid (severe) obesity with alveolar hypoventilationE66.3 — OverweightE66.9 — Obesity, unspecified

Common synonyms

Overweight and obesity

Frequently asked questions

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.