ICD-10-CM code · FY2027

E66 Overweight and obesity

Header codeNot billable: use one of the 10 billable codes below

About E66

Code: E66
Billable: No, header
Short description: Overweight and obesity
Block: E65-E68 Overweight, obesity and other hyperalimentation
Chapter: 4 Endocrine, nutritional and metabolic diseases
Code set: FY2027, October 1, 2026 to September 30, 2027

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Coding notes for E66

Excludes2 Not part of this condition, but a patient can have both: report both codes when both apply.

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

Code first Report the underlying condition's code before this one.

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

Use additional code Add a second code for the detail named here.

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

Chapter 4 notes (apply to every code in it)

Note

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.

Excludes1 Not coded here: never report these together with this code (use the code given instead).

transitory endocrine and metabolic disorders specific to newborn (P70-P74)

Codes under E66 13

E66.0 Obesity due to excess caloriesHeader
E66.01 Morbid (severe) obesity due to excess caloriesBillable
E66.09 Other obesity due to excess caloriesBillable
E66.1 Drug-induced obesityBillable
E66.2 Morbid (severe) obesity with alveolar hypoventilationBillable
E66.3 OverweightBillable
E66.8 Other obesityHeader
E66.81 Obesity classHeader
E66.811 Obesity, class 1Billable
E66.812 Obesity, class 2Billable
E66.813 Obesity, class 3Billable
E66.89 Other obesity not elsewhere classifiedBillable
E66.9 Obesity, unspecifiedBillable

Other categories in E65-E68

E65 Localized adiposityBillable
E67 Other hyperalimentationHeader
E68 Sequelae of hyperalimentationBillable

Latest research on obesity

Sleeve gastrectomy may produce greater and more durable weight loss than semaglutide in patients with obesityJan 30, 2026 · Chronic Disease
Oral semaglutide reshapes everyday obesity visitsJan 27, 2026 · Cardiology
The Scan by 2 Minute Medicine®: Oral GLP 1 reshapes obesity visits, deepfake doctors fuel DIY injectables, home longevity scales overwhelm clinics, and TV CPR scripts leave bystanders unpreparedJan 26, 2026 · Chronic Disease
Surgery-induced weight loss may be associated with lower mortality rates in women with obesity but not menJan 12, 2026 · Chronic Disease
GLP-1 receptor agonists show little effect on obesity-related cancer riskDec 8, 2025 · Chronic Disease

Landmark trials from 2MM Classics

Weekly semaglutide effective for decreasing body weight in obesity [Classics Series]Jan 1, 2025 · Gastroenterology Classics

More Endocrinology from 2 Minute Medicine

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ICD-10-CM FY2027 code set, as published by the CDC National Center for Health Statistics (NCHS) and CMS, effective October 1, 2026 to September 30, 2027. Codes, titles and notes are shown as published. Check payer rules and the official guidelines before billing. This page is not medical advice.