2026 ICD-10-CM Diagnosis Code E66.3Overweight

ICD-10-CM Codes›E00–E89›E65-E68›E66

ICD-10-CM E66.3
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E66.3 is a billable ICD-10-CM diagnosis code for overweight. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 640 through 641. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified nutritional and metabolic disorders.

Code Identity

ICD-10-CM Code
E66.3
Billable Status
Yes — Valid for Submission
Code Describes
Overweight
Short Description
Overweight
Same as the full description in the CMS dataset.
Parent Code
E66
Overweight and obesity

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE65-E68Overweight, obesity and other hyperalimentation
CategoryE66Overweight and obesity
This CodeE66.3Overweight

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Body mass index 25-29 - overweight
  • Developmental delay, overweight, facial dysmorphism, behavioral abnormalities syndrome
  • Fetal disorder due to maternal overweight
  • High body weight
  • Increased body mass index
  • Overweight
  • Overweight in adulthood with body mass index of 25 or more but less than 30
  • Overweight in childhood
  • Peripheral neuropathy due to overweight
  • Speech delay
  • X-linked intellectual disability, short stature, overweight syndrome

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Overweight

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR END016
Other specified and unspecified nutritional and metabolic disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Overweight

    a status with body weight that is above certain standards. in the scale of body mass index, overweight is defined as having a bmi of 25.0-29.9 kg/m2. overweight may or may not be due to increases in body fat (adipose tissue), hence overweight does not equal over fat.

  • 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.

  • Body Mass Index

    an indicator of body density as determined by the relationship of body weight to body height. bmi=weight (kg)/height squared (m2). bmi correlates with body fat (adipose tissue). their relationship varies with age and gender. for adults, bmi falls into these categories: below 18.5 (underweight); 18.5-24.9 (normal); 25.0-29.9 (overweight); 30.0 and above (obese). (national center for health statistics, centers for disease control and prevention)

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.

Convert E66.3 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
278.02 Overweight
Exact Match The mapping is direct, with no qualifiers.

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 E66.3Overview

Is E66.3 (Overweight and obesity) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report overweight on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does E66.3 group to?

When overweight is the principal diagnosis on an inpatient stay, it groups to MS-DRG 640, 641, with relative weights from 0.7782 to 1.3356 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of E66.3?

Under the General Equivalence Mappings, overweight converts to ICD-9-CM 278.02 (overweight). The mapping is a direct match.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.